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THE

PRINCIPLES, CONSTRUCTION, AND APPLICATION

OF PUMPING MACHINERY

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[ To face TilU-imgt. Missing Page THE PRINCIPLES, CONSTRUCTION, AND APPLICATION

OF PUMPING MACHINERY (STEAM AND WATER PRESSURE)

With Practical Illustrations of Engines and Pumps applied to Mining,

Town Water Supply, Drainage of Lands, etc. ; also Economy

and Efficiency Trials of Pumping Machinery.

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SECOND EDITION, REVISED AND ENLARGED.

WITH FRONTISPIECE, TWELVE PLATES, AND 279 ILLUSTRATIONS,

LONDON: CHARLES GRIFFIN & COMPANY, LIMITED, EXETER STREET, STRAND.

1905.

YAH Rights Reserved.'\

TABLE OF CONTENTS. VIU TABLE OF CONTENTS.

CHAPTER IV.

General Principles op Non-Rotative Pompinq-Engines.

PAGE

Principles of Cornish Engine, . 75 Waterworks Engines, 85 Mining Engines, .... 78

CHAPTER V.

The Cornish Engine : Simple and Compound.

The Cornish Engine, 88 Duty of Cornish Engine, 92 I

Cornish Engine Details, 91 I Duty Reports, .

CHAPTER VI.

Types of Mining Engines.

Various Types of Pumping-Engiiies, 102 Pump Rods, 122 Kley's Pumping-Engine, 104 Underground Engines and Pumps 126 Geared Engines, 106 Rotative Engine Underground, 130 Pumping Shafts, 110 Hugo Mine, .... 130 Example of Large Pumping-Plant, 118 Combined Direct-acting and Rod Pum ping-Engines, 119 pumping Engines, 133

Pit-head Frame, . 119 High Lift Underground Pumping System of Sinking the Shaft, 120 Engine, .... 134 Sinking Lifts, 122 Compound Cornish Cycle Pumjiing Plunger Lifts, 122 Engine, .... 135

CHAPTER VII,

Pit Work.

Pump Rods, . 142 Inclined Pit- Work, . . .160

I

Height of Lift, . 149 I Bucket Lifts for Sinking Purposes, . 152

CHAPTER VIII.

Shaft Sinking through Water-bearing Strata.

Colliery, . 1 a Flooded Bailing Tanks, . . 155 Unwatering 171

Pit Sinking, 158 I

CHAPTER IX.

Htdeaulic Transmission of Power in Mines.

174 Darey's Modification, 178 Explanation of the Principle, . Trial of the Engines, 185 Its Application at Saarbriicken, 176 Working Results of the Engine, 177 Later Improvements, 187 Armstrong's Method, 178 TABLE OF CONTENTS. IX

CHAPTER X.

Electric Transmission of Power to Pumps.

PAGE

High-Lift Centrifugal Pumps, . . 195 The Klein High-Speed Pumps, 199

Electrically-driven Plunger Pumps, . 199

CHAPTER XI.

Valve Gears of Pumping-Engines.

The Cornish Gear, . TABLE OP CONTENTS.

CHAPTER XVr.

Hydraulic Rams, Pumping Mains, etc.

PAGE PAGE

Hydraulic Rams, . . . .312 Hydraulic Mains, .... 322

Pearsall's Hydraulic Ram, . 314 Hydraulic Air Compressor, . . 324 The Taylor Hydraulic Air Compressor, 317 Sommeiller Hydraulic Air Com-

Syphons 319 pressor, . . .325

Inverted Syphons, . . . 321 Pohle's Air Lift Pump, . . 326

Index, 328 LIST OF FIGURES.

Fia. PAGE 1. Savery*s engine, ..... 2 2. Newcomen's engine, 6 3. Newcomen's engine with injection in the cylinder, 7 4. Hornblower's compound Cornish engine, 19

5. Hornblower's and Trcvithick's compound Cornish engine, 26

6. Sim's compound Cornish engine, 26

7. Diagram of steam engine losses, 28

8. Section of steam cylinder with Corliss valves in covers for reducing clearance spaces, .... 29

9. Condensing engines : Efficiency curve, 34

10. Non-condensing engines ; Efficiency curve, 35 11. Diagrams illustrating distribution of steam in various types of pumping- engines, ..... 44 12. Distribution of steam, Whitaore Pumping Station, 46

13. ,, Aston ,, 47 14. Arrangement of Cornish engine and feed-water heater, Aston Pumping Station, ..... 48 15. Indicator diagram, Boulton and Watt engine, 49 16. Feed-water heaters applied to Cornish cycle engine, 50

17. ,, applied to a Cornish cycle steam pump, 50 18. Bucket pump, ..... 61 19. ,, (double acting), 52 20. Plunger pump, .... 52 21. Bucket and plunger pump, 53 worked from beam engine, 54 22. ,, ,, 23. Piston and plunger pump, 55 24. Double acting piston pump, 55

25. 26. ,, plunger pump, 55 27. Three-throw plunger pump, 55 piunp, 55 28. ,, bucket without foot valves, 55 29. , ,,

30. Butterfly valves, . . • 56 31. Double-acting bucket pumps without foot valves, 57 32. Deep well pump without foot valves, 58 58 33. Shallow ,, ,, ,, 34. Well pump (Ashley's), 59 60 35. Double-acting well pump (Kestler's), . 36. Eeidler's piston and plunger pump with mechanically controlled valves. 61 , , ,

Xll LIST OP FIGURES.

FIG. PAQB 37. Reidler's quick reciprocating pump, vertical section, 62 38. plan. 62 ,, „ 39. pump, suction valve seating, 63

40, 41. Sections of, ,, 63 42. Types of pump valves, 64 43. 65 44. Husband's four beat valve, 66 45. Suction and delivery valves of multiple ring-type. 66 46. Half section of multiple ring valve, 66

47. Double beat valve with leather seat, . 66 48. Valve box with multiple valves on movable seating, 67 49. Multiple valve seating. 67 60. Plunger pump for pumping sewage having multiple hanging valves, 68 51. Section of air pump of condenser showing application of disc rubber valves 69

52. Bucket fitted with hat-band rubber valves, . 69 53. Foot valve of bucket pump with hat-band valves, showing application of

' fishing tackle ' for drawing valve and seating, 70

54. Pump displacement diagram : a pair of double-acting pumps with cranks at right angles, .... 71 55. Pump displacement diagi'ams : two single-acting pumps with cranks at right angles, ...... 71 56. Pump displacement diagram : three-throw single-acting pump, 72

67. ,, „ ,, ,. double- 72

58. Pump displacement diagram : three-throw double-acting pump with one pump out of action, ..... 73 59. Wippermann's air charger for air vessels of pumping engines, 74

60. Valve for maintaining constant pressure in pumping mains, . 74 61. Indicator diagram of Cornish mining-engine, 76 waterworks engine, 62. , , , 76 63. Velocity diagram from Cornish engine. 77 64. Distribution of steam in the author's compound Cornish engine, 78 65. Combined power diagrams of the author's compound Cornish engine 79 Diagram showing variation of force or strain in the author's compound Cornish engine, .... 79 67. Differential engine with double quadrants and double system of plunger pumps, ...... 81 68. Indicator card showing action of minimising shock. 82 69. Velocity diagram of differential compound pumping-engine, 82 70. Differential compound pumping-engine, South Durham Colliery, H.P. indicator card, .... 83 71. Differential compound pumping-engine. South Durham Colliery, L.P. indi cator card, ....". 72. Diagram illustrating effect of inertia in water columns, 83 73. Worthington compensating device, .... 84 curve of effect, 74. ,j ,, ,, ,85

76. Davey compensating device applied to well pumps, . 86 76, 77. Diagrams illustrating function of Davey compensating device

78. Cornish engine as applied to a mining shaft, . 79. Cornish engine, steam nozzles and valves, 90 80. Bull Cornish engine, ...... 91 81. Cornish engine steam cylinder, .... 92 82. Cornish engine air pump and condenser, 93 83. Davey's compound Cornish engine. Basset mines, 95 LIST OF FIGURES. XUl

FIG. PAGE

84. Compound Cornish engine, with parallel motion beams, . . .96

85. Cut-off motion for compound Cornish engine with parallel motion beams, . 96

86. Section of compound Cornish engine, Waihi Mines, . . . .97 87. Regniev's pumping-engine, ...... 103 88. Kley's „ ...... 104 89. American compound rotative engine for actuating a single line of pump rods, 106

90. ,, ,, ,, ,, ,, „ ,, 107 91. American geared pumping-engine, ...... 107 92. Geared pumping-engine with balance weights, .... 108

93. Elevation, compound Cornish engine, Waihi Mines, . . 109

Plan of ,, Ill 94. ,, ,, ,,.... 95. 96. Elevation and plan of compound engine placed directly over shaft with double line of pump rods, ...• 112 97,98. Valve gear and nozzles for compound donble-acting engine over shaft, . 113 99. Compound double-acting engine over shaft, ... 114 100. „ „ „ „ .... 115

101. Pumping-engine, Calumet and Hecla Mine, . 116

102. Barclay's grasshopper beam engine, . . 117

103. Small compound Cornish engine, . . . 118 104. Steel pit-head frame, Muke Mines, ..... 119 105. Compound differential pumping-engine elevation, showing valve gear, 120

106. ,, plan, .120 ,, ,, ...

section of steam cylinder, . 120 107. ,, ,, ,, 108. Air pump (section), ...... 121 109. Surface condenser, .... 122 110. Sinking lifts showing telescopic suction-pipe, . 123 124 111. General arrangement of plunger lifts, . . ... 125 112. „ „ .. • .... 113. Details of spear rods showing connection of rods for sinking lifts, . . 126 114. Details of jiump rods showing lowering rods and screws for sinking lifts, 127

115. Arrangement of Pelton wheels and lowering gear for sinking lifts, . 128

116,117. Details of Pelton wheels, . . 129 118. Plan showing Pelton wheels, ...... 129 119. Plan of plunger lifts showing position of sinking lifts, 130 120. Elevations and plan of plunger lifts, ..... 131 121. Detail of pump rods showing method of guiding or staying, . 132 122. Detail of pump rods showing catch pieces, banging beam, and rising main, 132

123. Compound Cornish engine, Waihi Mine, . . . 138 137 124. „ „ ' „ „ • •

125. Plunger pump, Waihi Mine, 700 feet lift, . . 138 126. Differential gear, Waihi Mine, .... 139 127. Compound Cornish engine, South Staffordshire Mines drainage, . 140 128. Couplings of wrought-iron pump rods, .... 142 129. Horizontal rotative engine with steel pump rod working on an incline, 143 130. Cornish pit-work, ...... 144 131. Details of Cornish bucket or sinking-lift, . 145

132. 133. Details of Cornish plunger pump, . . . . .146 134. Plunger pump in which the rising main is made to perform the function of a pump rod, ...... 147 135. Pumping-engine, capstan and man engine in inclined shaft, . 148 Pl'^n. 1^8 136. ,, ,, >, ...... 137. Details of plunger lift, rods and connections, as fixed in inclined shaft, 150 138. Modern bucket or sinking lift, ...... 161 ) , ,

XIV LIST OF FIGURES.

FIO. PAGE 139. Double beat valve, ...... 152 140. Suction valve, seating held in position by a hanging weight, 153 141. Mining kibble with valve in bottom for use in winding water, 156 142. Cylindrical tank with piston and valves for bailing water, 156 143. Galloway's tank for winding water. 157 144. General arrangement of tanks for winding water, 157 145. Galloway's tank for winding water from suspended tank, 157 146. Method of pumping during shaft sinking. 159 147. Plan of shaft showing arrangement of pump rods, rising main, etc., 159 148. Sinking pump suspended by rope blocks, 161

149, 150. Cameron sinking pump, . 162 151. Section of pulsometer, .... 163 152. Section of shaft No. 1 before tubbing, ZoUern Colliery, 164 164 153. „ ,, after ,, ,, 154, 155. Sections of shaft tubbing, ZoUern Colliery, 165

156, 157. Section of shaft, showing suction pipes of sinking lift, 167 158. Unwatering flooded colliery. Pit-head frame for suspending bucket lifts 169 in shaft, ...... 159. Unwatering flooded colliery. General arrangement showing bucket lifts 170 160. Unwatering flooded colliery. Plunger pumps, 171 171 161. jt »i )) j» 162. Hydraulic pumping, water rod system, 175 163. Underground hydraulic pumps. 179 164. Compound engine, hydraulic power transmission, 180 165. Section of steam accumulator, 181 166. S3'stem of hydraulic transmission. 187 167. Longitudinal elevation, triple expansion power engine 188

168. Plan of ,, ,, ,, ,, 189 190 169. Sectional plan and elevation of , , 170. Duplex hydraulic pump, 191

171. High-lift centrifugal pumps, Horcajo Mine, . 196

172. ), >j >) j> 197 173. Plan of power house and shaft, Horcajo Mine, 198 174. Method of supporting electric cables, Horcajo Mine, 199 175. Electrically driven plunger pump, 200

• • 201 176. )> »j ) 177. Cornish pumping-engine valve gear, front elevation, 204

side ,, 178. ,, ,, ,, 204 179. Cataract gear, Cornish pumping-engine, 205 180. Davey's differential valve gear. 205 181. Differential gear with cut-off and trip motion, 206

182. Differential trip gear for compound engines, . 207 183. Differential gear with cylindrical valves for compound engines. 208 184. Cataract gear worked by water pressure from pumping main. 208 185. Expansion and cushioning valves, compound non-rotative engine, 209 186. Shutter valve on back of main valve, 210 187. Meyer cut-off valve on the back of ordinary D slide valve, 210 188, 189. Corliss valve gear, ..... 211 190. Corliss valves, ....•• 212 191. Duplex steam pump valve motion, .... 213 (longitudinal 192. Cam motion to steam valve, crank motion to exhaust section] 214 (cross section), 193. ,, 215 194. Eccentric motion to main and expansion valves. 216 LIST OP FIGURES. XV

FIG. PAQE engine method of working valves, 195. Non-rotative ; .... 217 of 196. ,, „ method working expansion valve, . . . 218

197. Ti-iple expansion rotative pumping-engine with Corliss valves, . 219 198. Corliss valve motion, ...... 220 199. 200. Trevithick's water pressure pumping-engine, .... 222 201. Draining of dip workings, Griff Colliery, ..... 223

202. Longitudinal section of hydraulic pumping-engine, Griff Colliery, . . 225

203,204. Section and plan of engine valves of hydraulic engine. Griff Colliery, . 225

205. General arrangement of pumping-engine at Mansfield Salt Mine, . . 227 206. Hydraulic pumping-engine at Mansfield Salt Mine, .... 228 207. Details of engine valve, ...... 227 208. pump 227 ,, „ ...... 209. General arrangement at A. D. lead mine, ... . 230

210. ,, ,, of pumping-engine at A. D. lead mine, . . . 230

,, • • 211. ,, elevation , ,, n 231 212. Details of pumping-engine, A. D. lead mine, . .... 232

213. Hydraulic winding engine, A. D. mine, side elevation, . . . 233

214. ,, ,, ,, plan ,, . . . .233 215. Longitudinal section of cylinder and valves of hydraulic winding engine, A. D. mine, plan elevation, ...... 233

216. General arrangement of hydraulic pump, Hutton Henry Colliery, . 235

217. Longitudinal section ,, ,, ,, ,, . . . 235

218. Engine using same pipe for supply and delivery, longitudinal section, . 236 transverse 219. ,, ,, ,, ,, ,, . 236

220. Water pressure engine with heavy reciprocating parts, . . . 239 221. Davey's system of compensating for inertia in water pressure engines having a heavy mass to put in motion, .... 239 222. General arrangement, duplex hydraulic pump, . 240

223. Details of power cylinder and valves, duplex hydraulic pump, . 241

224. Diagram showing fluctuation in Birmingham water supply, 1896-97, . 246

225. Cornish engine, Wolverhampton Waterworks, . . 247

226. Compound beam engine, London Waterworks, . . . 248 Leicester Sewage Works, 249 227. ,, ,, .... 228. Triple expansion engine, Leeds Waterworks, ..... 250 229. ,,,,,,..••• • 251 230. Indicator diagrams for triple expansion pumping engine, Leeds Waterworks, 255

231. Combined diagrams from triple expansion pumping engine . . 256

232. Compound non-rotative pumping engine, Birmingham Waterworks . . 258

233. Parallel motion beams for compound pumping engine, . . 259

234. Triple expansion non-rotative engine, East London Waterworks, . 260

235. Cross compound rotative engine, Shanghai Waterworks, . . 261

236. Compound steam pump, Birmingham Waterworks, . . . 262

237. Horizontal compound Cornish engine, Birmingham Waterworks, . 263 238. Leavitt's triple expansion pumping-engine, ..... 264 239. 240. Davey's bore-hole system of wells for town water supply, . . 265

241. Compound non-rotative engine, Widnes Waterworks, . . .266 242, 243. Triple compound steam pumps, ..... 267

244. American triple expansion pumping-engine, . . 268

245. Compound non-rotative pumping-engine, Cambridge Sewage Works, . 269

246. 247. Method of lowering pumps in deep well, . . . 270

248. Four-cylinder non-rotative pumping-engine, Birmingham Watenvorks . 273 249. Triple expansion pumping-engine, East London Waterworks, Waltham Abbey, 283

250. Triple expansion pumping-engine. East London Waterworks, Lea Bridge, . 285 ,

XVI LIST OF FIGURES.

'251, Triple expansion pumping-engine, London Hydraulic Power Company, Wapping, ..... 252. Compound engine, Hampton Station, Southwark and Vauxhall Water Co.

253. Diagram illustrating the term 'load factor,' . 254. Scoop wheel, ..... 255. Centrifugal pump driven by Pelton wheel,

256. ,, ,, at Burnt Fen,

267. ,, ,, ,, details,

258. Details of pump spindle and onion bearing, .

269. Centrifugal pumps, Thompson's experiment, .

260-263. ,, ,, Parson's experiment, 264. (Diagram) Centrifugal pumps, Webber's experiment, 265. Simple hydraulic ram, 266. Leblanc's hydraulic ram, 267. Lemichel's hydraulic ram,

268. Pearsall's ,, ,,

269. Hydraulic ram with piston, . . ,

270. ,, air compressor (Taylor's system), .

271. Diagram of ,, ,, ,, 272. Ordinary syphon, .... in air collect, 273. ,, ,, which does not 274. Pumping main, syphon over hill, .... 275. Inverted syphon, ...... 276. Diagram illustrating flow of water in pipe of varying section, 277. Hydraulic air compressor, 278. Sommeiller hydraulic compressor, 279. Pohle's air lift pumps, ..... PUMPING MACHINERY.

CHAPTEE I.

EAELY HISTORY OF PUMPING-ENGINES.

History. —The elastic property of steam must have been observed in the

earliest period of man's history, but we have no record of its applica-

tion for power purposes earlier than 130 years before the Christian era. At that time Hero the Elder, a philosopher of Alexandria in the reign of Ptolemy Philadelphus, produced many mechanical contrivances, and among them a rotary steam engine, a mere toy, but an engine actuated by the reaction of a jet of steam. The first person in modern times who applied the power of steam to moving mechanism was an Italian mathematician, Giovanni Branca, who lived in Eome in the beginning of the seventeenth century. His invention consisted in making a jet of steam from a boiler impinge on the vanes of a wheel constructed like a water-wheel. In both inventions we have rotary

motion directly imparted to the mechanism by the reaction of a steam jet. These inventions were the forerunners of the steam turbine of to-day. It was not, however, by the extension of that principle that the steam engine

came into existence as a commercially valuable machine. The first practical application of the power of steam, as far as we know, was to raise water. In very early times small water jets or fountains were produced by the elastic force of steam acting on the surface of water in a vessel from which a pipe conducted the water to a jet or nozzle. It would appear to be an easy step in the invention of the steam engine, from steam pressure on the surface of the water, to steam pressing on a piston transmitting the pressure to the water ; but all the early attempts in employing steam to raise water were on the principle of the modern pulsometer, but were not self-acting.

In 1698 Saverij obtained a patent for raising water by the elasticity of steam, and in 1699 he had erected some engines and made a trial of one before members of the Royal Society. We take the following illustration

I —

PUMPING MACHINERY. and discussion on Savery's engine from Stuart's History of the Steam

Engine, published in 1826 :

"The first thing," says the ingenious inventor, "is to fix the engine

Fia. 1. —Savery's Engine.

(fig. 1) in a good double furnace, so contrived that the flame of your fire may circulate round and encompass your two boilers, as you do coppers for brewing. Before you make any fire unscrew G and N, being the two small EARLY HISTORY OF PUMPING-ENGINES. 3

gauge pipes and cocks belonging to the two boilers, and at the holes fill L,

the great boiler, two-thirds full of water, and D, the small boiler, quite full. Then screw in the said pipes again as fast and as tight as possible. Then

light the fire at b, and when the water in L boils, the handle of the

regulator, marked Z, must be thrust from you, as far as it will go, which makes all the steam rising in the water in L pass with irresistible force

through into P, pushing out all the air before it, through the clack r,

making a noise as it goes ; and when all is gone out, the bottom of the vessel P will be very hot. Then pull the handle of the regulator to you, by which means you stop 0, and force your steam through o into P^, until that vessel has discharged its air through the clack R up the force- pipe S. Tn the meantime, by the steam's condensing in the vessel P,

vacuum or emptiness is created, so that the water must and will necessarily

rise up through the sucking-pipe T, lifting up the clack M, and filling the vessel P.

" In the meantime, the vessel Fp being emptied of its air, turn the

handle of the regulator from you again, and the force is upon the surface

of the water in P, which surface being only heated by the steam, it does

not condense it, but the steam gravitates or presses with an elastic quality

like air, still increasing its elasticity or spring till it counterpoises, or

rather exceeds, the weight of the water ascending in S, the forcing pipe,

out of which the water in it will be immediately discharged, when once gotten to the top, which takes up some time to recover that power; which having once got, and being in work, it is easy for anyone that never saw the engine, after half an hour's experience, to keep a constant stream running out the full bore of the pipe. On the outside of the vessel you

may see how the water goes as well as if the vessel were transparent ; for as far as the steam continues within the vessel, so far is the vessel dry without, and so very hot as scarce to endure the least touch of the hand.

But as far as the water is, the said vessel will be cold and wet where any

water has fallen on it, which cold and moisture vanishes as fast as the

steam in its descent takes the place of the water ; but if you force all the water out, the steam, or a small part thereof, going through R will rattle the clack, so as to give sufficient notice to pull the handle of the regulator to you, which, at the same time, begins to force out the water from Fp,

without the least alteration of the stream ; only sometimes the stream of water will be somewhat stronger than before, if you pull the handle of the regulator before any considerable quantity of steam be gone up the clack better to let none of the steam off (for R : but it is much go that is but losing so much strength, and is easily prevented by pulling the regulator some little time before the vessel forcing is quite emptied). This being done, immediately turn the cock or pipe Y of the cistern X on P, so that the water proceeding from X through Y (which is never open but when turned on P, or P }i, but when between them is tight and stanch), I say, the water falling on P causes, by its coolness, the steam (which had such great ;

4 PUMPING MACHINERY. force just before, from its elastic power) to condense, and become a vacuum or empty space, so that the vessel P is, by the external air, or what is vulgarly called suction, completely refilled while P j? is emptying. Which being done, you push the handle of the regulator from you, and throw the force on P, pulling the condensing pipe over P p, causing the steam in that vessel to condense, so that it fills while the other empties ; the labour of turning these two parts of the engine— viz., the regulator and water-cock —and tending the fire being no more than what a boy's strength can perform for a day together, and is as easily learned as their driving of a horse in

after all, I would have men, and those, too, the most a tub-gin ; yet, apprehensive, employed in working the engine, supposing them more careful than boys.''

" In case it should be objected that the boiler must in some certain time be emptied, so as the work of the engine must stop to replenish the boiler, or endanger the burning out or melting tlie bottom of the boiler : to obviate this, when it is thought fit by the person tending the engine to replenish the great boiler, which requires an hour and a half or two hours' time to the sink- ing of one foot of water, then, I say, by turning the cock E of the small boiler D, you cut off all communication between the great force-pipe S and the small boiler D ; by which means D grows immediately hot, by throwing a little fire into B, and the water of which boils, and in a very little time it gains more strength than the great boiler, for the force of the great boiler being perpetually spending and going out, and the other winding up, or in- creasing, it is not long before the force in D exceeds that in L ; so that the water in D, being depressed by its own steam or vapour, must necessarily rise through the pipe H, opening the clack I, and so go through the pipe K into L, running till the surface of the water in D is equal to the bottom of the pipe H. Then, steam and water going together, will, by a noise in the clack I, give sufiicient assurance that D has discharged and emptied itself into L, to within eight inches of the bottom ; and inasmuch as from the top of D to the bottom of its pipe H is contained about as much water as will replenish L one foot. Then you open the cock E, and refill D imme- diately, so that here is a constant motion, without fear or danger of dis- order or decay. If you would at any time know if the great boiler be more than half exhausted, turn the small cock N, whose pipe will deliver water, if the water be above the level of its nottom, which is half way down the boiler ; if not it will deliver steam. So, likewise, it will show you if you have more or less than eight inches of water in D, by which means nothing but a stupid and wilful neglect, or mischievous design, carried on for some hours, can any ways hurt the engine. And if a master is suspicious of the design of a servant to do mischief, it is easily discovered by these gauge pipes ; for if he come when the engine is at work, and find the surface of the water in L below the bottom of the gauge-pipe N, or the water in D below the bottom of G, such a servant deserves correction though, three hours after that, the working on would not damage or

FLA 'I'E 1. [Tufuce h. 1 j,u,f:

NEWCOMKN ENGINE.

Ni-wi'ijiiH-ii l'iiiii|iini^r Kii.yiiic, lianlslry, m-ar Asliti)ii-uiii|i-i-Ij\ lie Out ol use- 1S3(I.

'Hi' fijlhiiriivj 111 !'. Vi.:v;^ Ki-e from ram/ Ph'./ogrnphs EARLY HISTORY OF PUMPING-ENGINES. 5 exhaust the boilers. So that, in a word, the clacks being, in all water- works, always found the better the longer they are used; and all the moving parts in our engine being of like nature, the furnace being made of Stourbridge, or Windsor brick, or fire stone. I do not see it possible for the engine to decay in many years ; for the clacks, boxes and mitre pipes, regulator, and cocks are all of brass, and the vessels made of the best hammered copper, of sufficient thickness to sustain the force of the working of the engine. In short, the engine is so naturally adapted to perform what is required, that even those of the most ordinary and meanest capacity may work it for some years without its receiving any injury, if not hired or employed by some base person on purpose to destroy it.'' This engine Savery applied for raising water for palaces, gentlemen's seats, draining fens, and supplying houses with water in general, and pumping water from ships ; and he erected many of them in different parts of England. The power of his engine he limited only by the strength of the pipes and vessels; "for,"' he says, "I will raise you water 500 or 1000 feet high, could you find us a way to procure strength enough for such an immense weight as a pillar of water that height; but my engine at 60, 70, or 80 feet raises a full bore of water with much ease." And comparing this performance of his machine with that by manual " labour, he continues : I have known, in Cornwall, a work with three lifts of about 18 feet each, lift and carry a 3|-inch bore, that costs forty-two shillings a day (reckoning twenty-four hours a day) for labour, besides the wear and tear of engines, each pump having four men working eight hours, at fourteenpence a man, and the men obliged to rest at least a third part of that time. I dare undertake that the engine shall raise you as much water for eightpence as will cost you a shilling to raise the like with your old engines, in coal pits, which is thirty-three pounds six shillings and eight-pence saved out of every hundred pounds ; a brave estate gained in one year out of such great works ! where £3000, £6000, or it may be £8000 per annum is expended for clearing their mines of water only, besides the charge and repair of engines, gins, horses, etc." In 1705 we find Savery associated with Newcomen and Cawley in a patent for condensing the steam introduced under a piston and producing a reciprocating motion by attaching it to a lever. Here was a combination of Savery's method of forming a vacuum with JSTewcomen's piston and attachment for producing a reciprocating motion for the purpose of working pumps.

The first Newcomen Engine (fig. 2) consisted of an open-topped cylinder, the piston of which was attached by means of a chain to a quadrant end of a reciprocating beam, the opposite end of the beam being attached in a-

similar manner to the rod of the pump ; the bottom of the steam cylinder

had a pipe leading to the boiler, in which was placed a stop-cock ; there was also a drain pipe from the bottom of the cylinder to draiu away the PUMPING MACHINERY.

water formed by tte condensed steam ; the cylinder itself was wholly enclosed in another cylinder of larger diameter, the annular space being iilled with water for the purpose of condensing the steam. The engine was actuated in the following manner : —Steam was first admitted into the cylinder until it was filled with steam, then the communication with the boiler was shut off, until the cold water surrounding the cylinder had

Fig. 2. —Newcomen's Engine.

condensed the steam, thus forming a vacuum ; the atmospheric pressure on the top of the piston then caused its descent, and the operation was repeated. A layer of water was kept on the top of the piston for the purpose of making it air-tight. The motion of the engine was a veiy slow one, especially as regards the indoor or pumping stroke, because of the time required to condense the steam in the cylinder by the transmission of heat through the metal of the cylinder.

It accidentally happened, however, in the working of one of Newcomen's '

EARLY HISTORY OF PUMPING-ENGINES.

engines, defect in that a the piston allowed the water above it to pass in the form of a jet into the cylinder. This caused the condensa- tion to become much more rapid, and the engine made a quicker stroke in consequence This accident led' to the abandonment of condensing by means of cooling the outside of the cylinder and to injection of water into the cylinder being adopted (fig 3); a further improvement was eflected in working the injection cock automatically by means of a buoy enclosed in a pipe attached to the cylinder. Even with this imperfect mechanism the engines were able to make from six to eight strokes per minute, and it is said that a boy named Humphrey Potter, who attended an engine, added a catch or scoggan, which in- creased the speed of the engine to fifteen or sixteen strokes per minute. We have no record what the contrivance was. The buoy which was employed to make the opening and closing of the injection valve self-acting might also have been made to lift a weight held by a catch and released by the motion of the beam, for the pur-

pose of working the steam cock, and it

is very possible that the word ' buoy has been confounded with the word

'boy.' It is hardly likely that boys were entrusted with the working of vx; engines requiring so much attention and adjustment. The buoy employed to make the engine-cock self-acting was the be- ginning of the complete automatic

action of the engine itself, and in- i*'iG- 3. —Newcomeu's Engine with injection in the volved a principle which is embodied Cylinder,

in all the automatic valve gears of non-rotative engines which have since been produced.

The first complete automatic engine of which we have any record is that by M. Francois, Professor of Philosophy at Lausanne, who proposed to work a pumping-engine on Savery's plan, giving motion to the stop- cocks by means of a tumbling water bucket turning on a pivot. The bucket was filled by a constant stream from a pipe, and when full toppled over, giving motion to the stop-cock, and becoming empty, a counter weight brought it back to its original position.

We do not know that Savery's engines were ever made automatic in this or any other way, but the Newcomen engine was made completely automatic by the valve gear designed by Mr Henry Beighton, an engineer of Newcastle-on-Tyne, in 1718. The leading feature in this gear was that of a tumbling weight which was raised during the stroke of the engine, so as to tumble over when the engine had completed its stroke, thereby opening the cocks or valves for the commencement of the return stroke ; the weight 8 PUMPING MACHINERY. tumbling in the one direction opened and closed tlie valves for one stroke, and tumbling in the other direction opened and closed the valves for the return stroke.

In Plate II. is reproduced from Pryce's Mineralogia Cornubiensis, by William Pryce of Eedruth, published in 1778, an illustration of the Newcomen engine of that day. In 1758 Emerson described in detail the Newcomen engine of that day. The description is so excellent that it is here reproduced, omitting the letters of reference to an accompanying engraving ; the description is clear enough without the engraving. It will be observed that the dimensions are given of an engine and pumps, and the reported con- sumption of coal ; neither the water pumped nor the consumption of coal can be correct. Description of the Engine. —^"The fire-engine to raise water has a great beam or lever, about 24 ft. long, 2 ft. deep at least, and near 2 ft. broad.

It lies through the end wall of the engine-house, and moves round a centre upon an iron axis. The steam cylinder is of iron, 40 in. diameter or more, and 8 or 9 ft. long, the piston sustained by the chain. The fire-place is underground. The boiler is 12 ft. diameter, which communicates with the cylinder by a hole and throat-pipe 6 or

8 in. diameter. The boiler is of iron, and covered over close with lead ; in this the water is boiled to raise steam. The regulator being a plate within the boiler which opens and shuts the hole of communication, this is fixed on an axis coming through the boiler, on which axis is fixed a horizontal piece called the spanner, so that moving the spanner forward and back moves the plate over the hole and back again. There is a horizontal rod of iron movable about a joint, and a piece of iron with several claws called the ' wye,' moving about an axis in a fixed frame.

The claw is cloven, and between the two parts passes the end of the spanner with two knobs to keep it in its place. There is the working- beam or plug-frame, in which is a slit, through which the claws pass and are kept there by a pin going between them. There is a leaden pipe called the injection pipe, carrying cold water from the cistern into the cylinder, and turned up at the end within the cylinder. To the injection- cock is fixed an iron rod lying horizontal. The end goes through a slit in the end of another piece, and on the end is a knob screwed on to keep it in place. There is a piece of iron with several claws called the ' eif,' movable about an axis. The claw goes through the slit in the plug-frame, and is kept there by the two pins ; the claw goes over the piece. As the piece is moved back and forward, the injection cock opens and shuts. There are several holes in the plug-frame that, by shifting the pins, serve to set the pieces higher or lower as occasion requires. There is the snifting clack balanced by a weight and opening outwards, to let out the air in the cylinder at the descent of the piston. In some engines a pipe goes from it to convey the steam out of the house. There is a leaden ^

E?

EARLY HISTORY OF PUMPING-ENGJNES. 9 pipe called the sinking pipe or eduction pipe going from the cylinder to the hot-well ; it is turned up at the end, and has a valve opening upwards ; this carries away the water thrown in by the cold-water pipe or injection pipe. There is the feeding pipe, going from the hot-well to the boiler, to supply it with water by a cock opening at pleasure. There are two gauge pipes with cocks, one reaching a little under the surface of the water in the boiler, the other a little short of it. By opening these cooks, it is known when there is water enough in the boiler, for one cock will give steam and the other water; they stand in a plate which may be opened for a man to go into the boiler to clean or mend it. There is the puppet-clack or safety-valve ; from this a wire comes through a small hole, to which is fixed a thread going over a pulley with a small weight at it ; the weight on the clack is about a pound for every square inch. There is a steam-pipe going from the clack out of the house. When the steam in the boiler is too strong, it lifts up the puppet-olack and goes into the steam-pipe, by which it is conveyed away; otherwise the boiler would burst. There is a pipe carrying water from the cistern into the cylinder to cover the piston to a good depth ; also a cook opening to any wideness that the water may run in a due quantity ; and a hole to let it out through a pipe into the hot-well when there is too much. There is a force pump, with a bucket and clack, and two valves opening upwards.

This pump is closed at the top, and being wrought by a lever it brings water out of a pit into a cistern for supplying condensing water. There are speers (spears), which work in wooden pumps within the pit. The cylinder is supported by strong beams going through the engine-house.

There is the first floor and the upper floor. At the end of the beam there are two pins, which strike against two springs of wood, fixed to

two timbers or spring beams lying on each side of the great lever ; these pins serve to stop the beam, and hinder the piston from coming too low in the cylinder. " When the engine is to be set to work, the water in the boiler must be made to boil so long till the steam is strong enough, which is known by opening the gauge-cocks. Then the inlet hole is opened by moving is let into the lets the spanner by hand ; then the steam cylinder which that end of the beam rise up; this raises the working beam or plug-

frame and moves the efF, which moves and opens the cold-water cook ; at the same time it moves the wye, and shuts the inlet steam-hole. The injection cock being opened, the cold water rushing into the cylinder is thrown up against the piston, and descending in small drops condenses the hot rarefied steam, and makes a vacuum under the piston. Conse- quently the weight of the atmosphere pressing upon the piston brings down the inner end, which raises the other end, which works the pumps. As the inner end descends, the working plug-frame descends, and, moving the efF and the wye, shuts the cold-water cock and opens the hole inlet for steam, and the steams goes into the cylinder, which takes off the pressure lO PUMPING MACHINERY. of the atmosphere, and the outer end descends by the weight of the speers and the inner end ascends as before, which opens the injection cock and shuts the steam inlet. So by the motion of the beam up and down the cock and holes shut and open alternately ; and by this means of condensing and rarefying the steam by turns within the cylinder, the lever or beam constantly moves up and down, by which motion the water is drawn up by the pumps, and delivered into troughs within the pit, and carried away by drifts or levels. At the same time the motion of the beam works the cold-water pumps, and raises water into the injec- tion-water cistern,

" When the engine is to cease working, pins are taken out of the plug-frame, and the cold-water cock is kept close shut while the inner end is up.

"The diameter of the pumps within the pit is about 8 or 9 in., and the bores of the pumps where the speers work should be made wide at the top, for if they be straight more time is required to make a stroke, and the barrels are in danger of bursting. Likewise, if water is to be raised from a greater depth at one lift, the pumps will be in danger of bursting ; therefore it is better to make two or three lifts, placing cisterns to receive the water. "The speers or rods that work in the pumps, consisting of several lengths, are joined thus : —each piece has a stud and hole, which are made to fit ; and the studs of one being put close into the holes of the other, and an iron collar drove upon them to the middle, they are then firmly fixed together. " There is never made a perfect vacuum in a cylinder ; for as soon as the elastic force of the steam within is sufficiently diminished, the piston begins to descend. The vacuum is such that about 8 lbs. presses upon every square inch of the piston, or in some engines not above 6 lbs. This engine will make thirteen or fourteen strokes in a minute, and makes a 6-foot stroke ; but the larger the boiler is, the faster she will work. "A cubic inch of water in this engine will make 13,340 cubic inches of steam,* which therefore is fifteen times rarer than common air. But its elastic force within the boiler is nerer stronger -or weaker than common air; if stronger, it would force the water out of the feeding pipe. This engine will deliver 300 hogsheads of water in an hour to the height of 60 fathoms. She consumes about thirty bushels of coal in twelve hours. In some engines there is a different contrivance to open and shut the regulator, which is performed thus : —As a beam ascends, it turns the wye about its axis, causing a weight to fall and strike a smart blow on a pin, and shuts the regulator. And when the beam descends, a similar action opens the regulator. There is a cord fixed at the top of the wye to hinder it from and shutting the injection going too far on each side ; likewise for opening

* The real volume is 1642. ;

' EARLY HISTORY OF PUMPING-ENGINES. I I cock, instead of the pieces described. Some engines have quadrant wheels with teeth, which, moring one, the other opens or shuts the cock of the injection pipe.*

" In some engines there is a catch held by a chain fixed to the great beam, and this catch holds the injection-cock lever or eff from falling back and opening the cold-water cock, till the rising of the beam pulls the catch up by the chain, and then the eff falls.'' From the above description, written twenty-nine years after New- comen's death, it is evident that the atmospheric engine was largely in use. The writer of it speaks of some engines differing from others in details. Engines were at work in most of the mining districts of England.

In this year (1758) many engines were at work in Cornwall ; and it appears that in that county Newcomen erected an engine in 1720, or two years after Beighton's invention of the hand-gear. It is said that his first engine in Cornwall was erected in 1714, but there are no definite records. In 17G9 Smeaton computed the duty of fifteen engines in the Newcastle district, and one year later made note of eighteen large engines in Cornwall, eight of which had cylinders 60 to 70 in. diameter. A Calculation of the Cylinder and Pumps of the Fire-Engines. — "If it be required to make an engine to draw any given number of hogsheads of water in an hour from / fathoms deep, to make any number of strokes in a minute by a 6-foot stroke, find the ale gallons to be drawn at one stroke, which is easily found from the number of strokes being given.

" Let 5r = number of ale gallons to be drawn at one strolie. = diameter (in inclies). ,, p pump's

,, c = cylinder's diameter (in inches).

Then = \/f>g p ; and supposing the pressure of the atmosphere on an inch of the piston to be 7 lbs., thenc=V-^=\/^^-

" Note, if instead of 7 lbs. you suppose the pressure of the atmosphere to be 1 lb., and instead of a 6-foot stroke to make an r feet stroke

then^ = x/-x5?. 'iiid c = \/^^ll^IJi.'

The author has here arranged the events in connection with the subject in their chronological order ; and it is interesting to observe that, though Watt had finished his labours in Cornwall in 1800, bringing the duty of his engines up to 20 millions, yet, between 1810 and 1821, three Newcomen engines were erected at the Farme Colliery in Scotland. In those days the want of knowledge of what others had done formed a great

* This is the Beighton gear or tumbling-weight device, Plate IL From the above description it is clear that the plug-frame was in use without Beighton's device, and probably before it. — —

12 PUMPING MACHINERY. bar to progress. By the publication of what has been accomplished, and by the knowledge thereby imparted, the progress of mechanical science and arts has been hastened during the last fifty years as much as by the theoretical teaching of schools.

2%e Neweomen Engine. —Events in chronological order : 1696. Description of Savery's Fire-Engine, published in the Philosophical Transactions of the Royal Society. 1698. Thomas Savery, of London, obtained a patent for raising water by the elasticity of steam. His engine had no piston. 1702. Savery's Miner's Friend was published. Savery's advertisement in Post Man, 19th-21st March, notified that his engine might be seen at work "at his workhouse in Salisbury Court, London." This advertisement was reproduced in Notes and Queries, 27th January 1900. 1712. Neweomen erected an engine near Dudley Castle for Mr Back of Wolverhampton. It had a water-jacket around the cylinder for

condensing the steam : but afterwards injection in the cylinder was adopted. All valves were worked by hand. 1712 to 1718. A buoy was used to give automatic action to the injection cock. 1714. A Neweomen engine is said to have been erected at "Wheal Vor,

near Breage, in Cornwall ; and another at Ludgvan in 1720. 1715. Savery died in London. 1717. 29th December. —Galley (or Cawley) died whilst erecting an engine at or near Ansthorpe, Yorkshire. This is from the burial

register of Whitkirk. See Earey's Steam Engine, p. 155. 1718. Beighton invented the hand-gear. The steel-yard safety-valve

was introduced ; also the snifting valve, and the shortened eduction pipe with its non-return valve. All the essential features of the perfected engine were now present. 1720. Neweomen went into Cornwall and erected an engine at Wheal Fortune, St Day. Another engine on the same model was erected at Pool Mine, Cam Brea, in 1746. 1721. An advertisement appeared in the Daily Courant, 24th July 1721, beginning " Whereas an engine to raise water by Fire, commonly called Savery's engine ....," and inviting attention to a new form of engine. The above was printed in Notes and Queries, 27th January 1900. See also Notes and Queries, i7th February 1900, for a communication from J. E. Hodgkin. 1725. Joseph Hornblower erected an engine at Wheal Eose, Truro; a second engine was erected at Wheal Busy, Chacewater; and a third at Polgooth, near St Austell. 8th April. —Steam engine at work at Tipton, Staffordshire. [On this day the son of John Hilditch, "Manager of y" Fire Engine at Tipton," was baptised in the Parish Church of Bilston. The Engineer, 11th Nov. 1898.] 3

EARLY HISTORY OF PUMPING-ENGINES. 1

1729. Newoomen died in London. 1733. 24th July. —Savery's patent expired, having been in existence for thirty-five years. 1758. Many engines at work in Cornwall, one at Herland, near Gwinear, having a 70-in. cylinder. Emerson describes in detail in his Principles of Meclianics the Newcomen engines as then used. 1767. Smeaton first turned his attention to the atmospheric engine. 1769. Smeaton computed the duty of fifteen engines in the Newcastle-on- Tyne district, and found the average duty to be 5'59 millions of

foot lbs. per bushel or 84 lbs. of coal.* 5th January. —Watt's first patent. 1770. Smeaton made note of eigliteen large engines in Cornwall, eight of

which had cylinders from 60 to 70 in. diameter. 1772. Smeaton made improvements in details, not altering the general

construction, and succeeded in obtaining a duty of 9 '5 millions. 1775. Smeaton erected a Newcomen engine at Chacewater in Cornwall, the steam cylinder 72 in. diameter. Water load 7§ lbs. per square inch. Lift of pumps 306 feet. This engine was altered by Watt to his system.! 1810. A Newcomen engine was erected at the Farme Colliery, Eutherglen,

near Glasgow, for winding and pumping ; in 1820 another was added for winding; and in 1821 a third, having a 60-in. cylinder, for pumping. From 1720 to 1740 few engines were erected in Cornwall, because of the high duty on sea-borne coal. In 1741 an Act of Parliament was passed for the remission of the duty on coal used for fire-engines for draining tin in the and copper mines county of Cornwall. J The effect of the passing of this Act was that by the year 1758 many engines had been brought into use ; one engine at Herland had a 70-in. cylinder. Rotative Atmospheric Engines. —It appears that attempts were made as early as 1768 to produce a rotative motion from a Newcomen engine; but it was not till about 1780 that it was successfully accomplished by the use of the crank. It does not appear that any attempt was made, before Watt's separate condenser was invented, to reduce the cooling effect of the injection water in the cylinder by effecting the condensation in a small vessel attached to the cylinder. It is evident, however, that, after Watt's patent,

* The bushel was taken as 84 lbs. in Savery's time.

t A drawing of almost the first Watt engine for the Birmingham Canal is shown in the Frontispiece. X The Act referred to is the 14th Geo. II., Cap. xli., and intituled: —An Act for granting to His Majesty the sum of one million out of the sinking fund, and for applying other suras therein mentioned for the service of the year 1741 ; and for allowing a Draw- lack of the Duties upon Coals iised in Fire-Engines for draining Tin and Copper mines in the County of Cornwall^ etc, . . . 14 PUMPING MACHINERY.

JSTewcomen engines were made with outside condensers without air-pumps, the air being discharged through a snifting valve. Such condensers were known as 'pickle-pots.'

In fig. 1, Plate III., will be found a sketch of the ' pickle-pot ' condenser.

It is more than probable that such condensers were not known till after Watt's invention of the separate condenser, and that they were applied to improve the economy of the Newcomen engine and to evade "Watt's patent.

In fig. 5, Plate III., will also be found a diagram constructed by the author to indicate the economy of fuel resulting from various improve- ments, commencing with the earliest engines of Newcomen. A diagram above also indicates the increase in steam pressure corresponding to the increased economy. The Newcomen engine had now been brought to a state of perfection, in which it remained, except as regards improvements in workmanship, up to the time when Watt made his great invention of the separate condenser. Watt's attention was first directed to the subject of the steam engine by Dr Kobinson, then a student in the University of Glasgow, in 1759. In 1761 or 1762 he made some experiments with a small model of a steam cylinder, but the attention necessary to his business—that of a mathematical instrument maker—prevented his pursuing the subject any further at that time. In the winter of 1763 and 1764, having occasion to repair a model of Newcomen's engine belonging to the Natural Philosophy Class of the Glasgow University, his mind was again directed to the subject. When the model was set to work, he was surprised to find the great volume of steam condensed with a moderate quantity of injection water. By sub- sequent experiments Watt ascertained that steam was 1800 times rarer than water. In another experiment, being astonished at the large weight

of water required for injection and the great heat that it acquired from the

small weight of water in the form of steam, which had been used in

filling the cylinder, and not understanding the reason of it, " I mentioned it," he says, " to my friend Dr Black, who then explained to me his doctrine of latent heat, which he had taught some time before this period

but having myself been occupied with pursuits of business, if I had heard of it, I had not attended to it, when I thus stumbled upon one of the material facts upon which this beautiful theory is founded." Dr Ure gives the conversation which he had with Watt oft this subject, in which Watt describes the simple but decisive experiments by which he discovered the latent heat of steam. His meaus and leisure not then permitting an

expensive or complex apparatus, he used apothecaries' phials ; with these he ascertained two more facts—first, that a cubic inch of water would form about 1 cubic foot of ordinary steam, or about 1728 cubic inches- and that the condensation of that quantity of steam would heat 6 cubic inches of water from the atmospheric temperature to the boiling point. He also saw that six times the difference in temperature, or fully 800 deorees of heat, had been employed in giving elasticity to steam, and which must PLATE 111.} [To fno' page 14.

NEWGOMEN ENGINE.

Explanatory Diagrain.s.

\"(!/fli/l i'pi7i//fi/\'

h/'i/i nil .nil ill I

liilirlion (ilk

I'liii'v III f'lfr alliuli.ul /,. t\ liu-hwl,; -

Fig. 3. — Illustration of '' llif " Hiioy ;ini.l the " Scrot^^gaii " in tiie Fig. 2. —Sketch illustrating Ne\\'c'omt;n EiitrinL'. the Newcoiiieii Engine he- lore it was made automatic, 1772-1718.

''\ ^ Fir.. 1. — • I'ickle-pot." Fig. 4. — Illustration of the " Cataract " snh- stituted for the "Buoy" ill Modern Engines.

1770 1800 issu

Fig. 5. —Pumping Engines.

5

EARLY HISTORY OF PUMPING-ENGINE8. 1

be all subtracted before a complete vacuum could be obtained under

the piston of a steam engine. On reflecting further, it appeared to him that a cylinder should always be kept as hot as the steam that

entered it.

It occurred to Watt in 1765 that for the purpose of avoiding the cool- ing of the steam cylinder, the condensation should be effected in a separate vessel, and in 1769 we find that he took out a patent for his invention of the condenser, and the use of oil and tallow for lubricating the piston. It next occurred to Watt that the mouth of the cylinder being open, the air vrhich entered above the piston would cool the cylinder. He therefore provided the top of the cylinder with a cover, and on the com- pletion of the steam stroke, communication was opened between the space

above the piston to that below it, thus placing the piston in equilibrium.

The piston was then raised to the top of the cylinder by the weight of the pump rods. Communication between the top and the bottom of the cylinder was then closed, and whilst steam was being admitted to the top

of the piston for the next stroke, the steam below it was admitted into the separate condensing vessel. Watt made a small model of this engine, in which the condenser was simply a tin tube with water on the outside

forming a surface condenser ; an air pump was added to keep the condenser evacuated. Watt, however, found that the condensation arising from the cooling of the outside of the condenser would not be rapid enough unless the

surface of the condenser was made very large ; he therefore resorted to the method of injecting water into the condenser, as water had been injected into the Newoomen engine. The Watt engine was now complete. In the year 1775 Watt entered into partnership with Matthew Boulton, of Birmingham, and soon after Boulton & Watt commenced the manufac- ture of Watt's engines, and some were erected in the coal mines of Stafford- shire and Warwickshire and other places ; but it was in Cornwall that Watt found the great field for the development of his invention. Coal was there very expensive, having to be brought from South Wales, and the mines were becoming deep and exceedingly costly to drain. The pro- prietors of the mines were, however, unwilling to be at the expense of taking out the old atmospheric engines, and of replacing them with Watt's improved engine ; to meet that objection Messrs Boulton & Watt erected many engines at their own expense, taking as payment one-third the saving effected in coal, and it is said that in one mine at Chacewater three of Watt's engines were erected, and the proprietors of the mine engaged to pay .£800 per annum for each engine as a compromise for the third part of the saving made in coals. The expansive power of steam was understood by Watt in 1769, and was afterwards particularly described in his patent specification of the 25th of October 1781. Watt had a very clear idea of the economy to be effected 6 —

1 PUMPING MACHINERY.

by expansive working ; in his patent specification he gives the following statement :

M''hen the cylinder is quite full, its performance will be as I'O "7 as . When J full, its performance is increased . 1

>• .21 ,, h ,, ,,

„ i „ ,, ., • 2-4

• 2-6

• 2-8 3-0 3-2 upon the supposition that steam contracts and expands by variation of pressure in the same ratio that air would do. At that time the Watt engines were all employed in working bucket or lift pumps, and it was not until a much later date that the plunger pump was introduced. As long as bucket pumps only were used the extent to which expansive working could be carried was very limited, for reasons we have fully gone into in a subsequent chapter dealing with the principles of Cornish and other direct-acting engines. Cornwall formed the great nursery of the pumping-engine. In the early part of the last century many of the mines which were drained by means of water-wheels had reached such a depth that the power available was not suffi- cient, and the mines were in consequence on the point of being abandoned. Savery failed in his attempts to introduce his engines into Cornwall, but it is said that a Savery engine was for many years employed at Kier's Manufactory, St Pancras, London. It was employed in raising water to turn a water-wheel 18 ft. in diameter, which wheel was applied to the purpose of giving motion to lathes, etc. It was stated to consume six bushels of good coals during twelve hours' work, and to make ten strokes per minute, lifting 7 cubic feet of water per stroke through a vertical height of 20 ft. This in round numbers is at the rate of 70 cubic 70x63x20 2-6„^^^^ feet per mintue, or —.,., />q^— = H.r.

The consumption of coal per horse power per hour was then — = 16'1 lbs., and the dynamic duty on 84 lbs. of coal about 10,296,000 foot lbs. This must, however, be regarded as an incorrect statement of the actual duty. In 1774 Mr Rigby put up two of Savery's engines at Manchester to work water-wheels, which engines operated by means of suction. The duty was found to be five and a quarter million foot lbs. with one, and five and a half millions with the other, for a consumption of one bushel of coal or 84 lbs. About the year 1767 John Smeaton devoted himself to improving the condition of the atmospheric engine, and with very marked success. Smeaton had in his nature so admirably combined the virtues of untiring skill and enterprise together with a comprehensive scientific knowledge, and a keen preception of the wants of the age, that any subject which he took in hand had thereby its guarantee of success. Smeaton caimot be 7

EARLY HISTORY OP PUMPING-ENGINES. 1

remembered for any one invention, but his improvements in the various

details of the engine completely metamorphosed it, and he succeeded in increasing the duty thereby nearly 50 per cent. In 1775 Smeaton erected at Chaoewater Mine, in Cornwall, an atmos-

pheric engine with all his improvements ; this was the largest atmospheric

engine probably ever put up. The cylinder was 72 in. diameter, and the

stroke of the piston 9|- ft. ; the water load was equal to 7-| lbs. per square

inch of the piston, and the lift was 306 ft. " It had, when originally

erected, one boiler, 15 ft. diameter, placed immediately under the cylinder, and an extra one, constructed to collect and make use of the waste heat from the furnaces upon the works. This latter, however, being found a

failure, it was removed after a very short use, and two new boilers of the same construction and dimensions as the centre one were added, being fixed in low buildings on each side of the engine-house. These were found * successful in furnishing the engine with steam." This engine was erected to supply the place of two atmospheric engines which had previously been worked on the same mine —one with a 64-in.

cylinder, and the other with a 62-in. cylinder, each having a stroke of 6 ft. Mr Smeaton reported the duty of the new engine to be greater than that

of the old ones in the proportion of 7 to 4. In 1769 Smeaton tabulated the duty of fifteen atmospheric engfties at work in Newcastle, giving the mean duty of 5'59 million foot lbs. per one bushel of coal. Soon after, he obtained from a new engine a duty of 9"45 millions. He ultimately raised the duty of the atmospheric engine from

7 to 10 millions. He arranged his pit- work much in the same way as it is

done now as regards the disposition of the various lifts. The pumps were of the bucket type, with butterfly and clack pump valves. In his direction " for the Chacewater engine, he says : The durability of the leather of the bucket depends greatly on the proper proportions and construction of the bucket hoops. The bucket hoops on the outside should be a cylinder, that

is, the same diameter above and below ; their taper inside must, therefore,

be formed by the different thickness of the metal ; their external diameter should not be more than one quarter of an inch less than their respective

working barrels ; the hoops to be made as broad as can be allowed." Butterfly valves, with two semicircular flaps opening back to back on a joint or hinge, fixed across the middle of the bucket or clack, were used

for all the common sizes. For pumps from 18 in. to 20 in. in diameter it was usual to divide the valves into four flaps.

The first engine erected by Watt in Cornwall was one with a cylinder

30 in. in diameter, fixed at Creegbraws, near Chacewater, very soon after Smeaton's engine at Chacewater, probably about 1776. It worked there a few months, and was then removed to Wheal Busy, where it remained in action for some time afterwards. In 1777 the patentees erected three more engines — namely, at Titig-

* Pole on The Cornish Engine, 2 I» PUMPING MACHINERY.

tang, Owan-vean, and Tregurtha Downs. These were of larger dimensions ; two of them had cylinders 63 in. in diameter, and were capable of working with a load of 11 lbs. or 12 lbs. on the square inch of the piston. The first-named of these three, that at Ting-tang, was put up with the concurrence of one of the Hornblowers, who was engineer to the mine at the time. In Watt's first engines —and in this among the number—the air-pump and condenser were exhausted previously to starting, by means of a small pump worked by hand, and on the first trial the engine suddenly started and killed the man who was working the pump. Watt, who was present at the time, afterwards added the arrangement of blowing through, in order to produce the vacuum at starting by condensation. The success of these trials induced the rapid adoption of the improved

field of profit to the engine, and rendered Cornwall the richest patentees ; for in about twelve years the whole of the atmospheric engines in the dis- trict had been replaced by patent ones, whose dimensions varied from 24-in. to 66-in. cylinders, and many of them were double-acting. The extension of the mining operations kept up a constant demand upon the manufacturers of the engines, either for new machines, or for the enlargement of old ones, which lasted until the year 1800, when the monopoly expired, and the con- nection of Messrs Boulton k Watt with the county entirely ceased. From the date of Watt's patent for expansive working—namely 1781 — to the present time^ the development of the pumping-engine has been, in the advances made in the application of the principle of expansive working under mechanical conditions, best suited to the nature of the work to be done. Watt proposed to work with increased expansion by using mechanical devices, by means of which the resistance of the pump was gradually lessened from the beginning to the end of the stroke of the engine, but he appears not to have carried his idea into practice. He, however, employed expansive working, as far as it was practicable with the system of bucket pumps then in use. About the year 1738 Newcomen introduced into Cornwall an engineer and manufacturer of steam engines, one Jonathan Hornhlouier, who soon became one of the principal manufacturers of steam engines in that county. Young Jonathan, a son of the above-named Hornblower, after serving an apprenticeship with a pewterer and plumber at Penryn, turned his attention to engineering, and soon became one of the principal engineers of the

Cornish mines, which occupation he held till his death in 1812. He was much esteemed by all who knew him, and displayed great talent as an engineer. In 1776 Hornblower turned his attention to the carrying out of the principle of expansion which he had previously conceived, and he made a large working model with cylinders 11 in. and 14 in. in diameter. He patented the invention in 1781, or about one year before the date of Watt's patent. The mode of carrying out the expansive principle invented by Horn- blower is identical with that now commonly known, incorrectly, as Woolf's —

EARLY HISTORY OF PTTMPING-ENGINES. 19 iiiTention, and consists in what is called the double-cylinder expansive engine. The steam is first admitted into a small cylinder, and after doing its work there, without expansion, is allowed to escape into a much larger cylinder, where it becomes expanded. It is difficult to imagine that Hornblower could have worked out the details of the double-cylinder engine without assuming that the theoretical value of expansion would be

the same whether one or two cylinders be used ; and it is probable that he saw the mode of working expansively in a single cylinder, but imagined that practical difficulties were in the way of its being carried to any great extent without the use of the second cylinder. Watt's patent was subse-

7 v//////////^///////////.

I

"^77777^77)77

Fig. 4. —Hornblower's Compound Cornish Engine.

quent to Hornblower's, so that Hornblower could not have introduced tne second cylinder to evade Watt's claim.

Hornblower's engine is illustrated in fig. 4. The progress made up to the year 1800 is given in the following summary : 1776. —Watt stated in a letter to Smeaton that his engine at Soho raised between 20,000 and 30,000 cubic feet of water 90 feet high with

120 lbs. of coal, which would be equal to 21,600,000. This was more, however, than Boulton & Watt would engage to perform,

as, in a letter written by Boulton to the Carron Company in this year, which contained proposals for erecting an engine, he 20 PUMPING MACHINERY.

stated the performance as equal to about 19,000,000. Smeaton,

about this time, after many experiments, laid it down as a rule that Watt's engines would do double as much as his own, which, as we see above, was 9'4o millions, consequently 18,900,000. 1778-1779.—Watt having stated that his engines should do 23,400,000, Smeaton made trial of two—one on the Biimingham Canal and one at Hull Waterworks, and found the duty of one equal to 18,000,000, and of the other 18,500,000.

1778. —Boulton Camborne, but in these the steam was not raised higher than before, and the piston made a considerable part of the stroke, therefore, before the steam valve was closed. 1(98. — As a consequence of a suit respecting their patent, which was carried on by Boulton & Watt and others, an account of the duty of all the engines in Cornwall was taken by Davies Gilbert and Captain Jenkins of Treworgie, and they found the average to be about 17,000,000. An engine at Herland was found to be the best in the county, and was doing 27,000,000 duty, but, being so much above the average, some error was apprehended. This engine was probably the best then ever erected, and attracted, therefore, the particular attention of Boulton & Watt, who, on a visit to Cornwall, went

to see it, and had by many experiments tried to ascertain its duty. It was under the care of Murdock. Captain John Davey, the manager of the mine, used to state that it usually did a duty

of 20,000,000, and that Watt, at the time he inspected it, pro- nounced it perfect, and no further •improvements could be expected.

1 '00. —About this time Boulton

EARLY HISTORY OF PT7MPING-ENGINES. 2 1 engines of Cornwall doing a duty of not over twenty millions, but within forty years after the Cornish engineers raised the duty more than threefold. From Lean's Historical Statement we have the following particulars of the period between 1801 and 1811 : "About the year 1801 Captain Joel Lean (who, besides being an experienced miner, was a good practical engineer) was appointed principal manager of Crenver and Oatfield Mine in the parish of Crowau, one of the deepest and most extensive mines then at work in the county. He found the engines and pit-work in a very bad condition. The mines were about 170 fathoms deep from the surface and 140 fathoms below the adit; and the water was drained by three steam engines—viz., a 63 in. cylinder double, on Bull's mode of construction, having the cylinder over the shaft and the piston rod working through the bottom, and 60 in. and 36 in. cylinder single engines on Boulton & Watt's plan. The consumption of coals by these engines was enormous, and the average duty was ten millions ; Bull's engine, 63 in. double, consumed fourteen chaldrons of coal in one day. The pit>work, too, which consisted of leathern buckets with two or three pistons, such as were at that time in general use for plungers, was in a very bad state ; and it may be safely asserted that the engines were idle at least one-third of the time, for the purpose of repairing the pit-work and changing the buckets. "After he had assumed the management. Captain Lean's attention was immediately directed to the pit-work, and here he first introduced (what is now so generally used, and with so great advantage) the plunger pole, instead of the common box and piston, wherever he found it practicable. Equally bold and successful was the change which he made in the engines. The two smaller (which were erected in the same house and connected with the same rods) he threw aside, and put in their stead a 70 in. cylinder —the first of the size ever erected in the country—in which he adopted the expansive mode of working, at that time so little thought of and very partially practised. These improvements saved the mine. At that time they were burthened with a debt of many thousand pounds, which was continually augmenting ; but as they consumed less than half the previous quantity of coal, and at the same time kept the mine effectually drained, so that the miners could work without hindrance, they not only discharged the debt, but obtained considerable profit." We have been thus particular respecting what Captain Lean did at Crenver and Oatfield, because of the important consequences which resulted from the improvements introduced by him into the engines and pit-work of those mines. For being sensible that the defects which he had removed with so much advantage were not confined to the engines under his care, and convinced that it would be attended with much good, if the public generally, and more especially those who were adventurers in mines, had the means of comparing the different engines with each other, he endeavoured to bring some others of the principal managers into —

2 2 PUMPING MACHINERY.

his views, and to awaken them to the necessity of registering and publish- ing the duty performed. It was, however, not imtil after many years that his wishes were accomplished. The two governing facts which led to the great advance in duty was first, the introduction of the plunger pump in place of the bucket, an alteration which gave quite a new character to the pit-work and thereby made increased expansion possible ; second, the publishing of Lean's Monthly Duty Records, which held out an inducement to engineers to rival each other in the duty which they obtained from their engines, a matter which was of vital importance to the mine owners. The result of the rivalry was that the best engines were brought to such a high state of perfection that the efficiency ratio was as great as that of the best engines of to-day—that is to say, the Cornish engine made as good use of its opportvmities as the triple-expansion engine does ; but the opportunities of the Cornish engine were liiiiited by steam pressure of 45 lbs., whereas the triple engine is now worked with pressures as high as 150 lbs. It was fully recognised that the economy of the engine depended largely on not wasting heat in radiation, or, in other ways, having dry steam, ex- panding the steam down to an absolute pressure of about 5 to 6 lbs. per square inch, and securing a good vacuum. The pressure of steam avail- able was only from 20 to 30 lbs. per square inch, and although some engines were working with a boiler pressure of 40 lbs., that was the limit of pressure at which the full expansive power of the steam could be utilised in the single cylinder Cornish engine. The idea of compounding the Cornish engine, originated by Hornblower, was taken up, and many compound engines were erected by Trevithick, Gribble, Sims, Woolf, and others, and although some of the engines did a good duty, no better results were obtained than with the best single cylinder engines ; some of the compound engines were not properly designed for the best effect, but as long as the boiler pressure remained low, the compound engine had no raison d'etre. In 1824 Woolf erected a compound engine at Wheal Alfred Mine, intended to be worked with cast-iron boilers at 100 lbs. pressure, but owing to the failure of boilers the engine was removed.

' It must be observed that the method of duty reporting ' adopted in Cornwall applied to the engine and boiler as a whole ; there was no indication of how far the results were influenced by a good or a bad boiler, or good or bad coal, nor were the observations which formed the basis of the reports taken with sufficient accuracy for strictly scientific purposes. There was the error of uncertainty of length of stroke, and the load of the engine was calculated from the size and length of the lifts. As long as the lifts were vertical no error could arise in that respect, but frequently the lifts were inclined, so that the length of the lift did not represent the height of watei'. It was, however, considered by the Cornish engineers that the extra friction of the inclined rods made up for the deficiency in —

EARLY HISTORY OP PUMPING-ENGINES. 23 height of water. As regards the coal used, it was probably fairly uniform in quality, as it was all South Wales coal. The efficiency of the boilers was also fairly uniform after the introduction of the Trevithick Cornish boiler, which took place about the year 1813.

Notwithstanding the defects in the system of ' Reporting,' the reports were of commercial value to the proprietors of the mines, and were useful to others as indicators of engineering progress, but if we had no better record of the thermal efficiency of the Cornish engine than that given in the reports, we could form no proper judgment in the matter ; the Cornish engine has, however, had an extended application beyond the Cornish mines, and has been subject to rational and complete tests in the same manner as other engines.

The progress of events after Watt left Cornwall up to 1834 is given in the following summary : 1810. —^Woolf returned to Cornwall and introduced his engine working high-pressure steam in a small cylinder, and expanding into a

larger one ; Captain Richard Trevithick also invented the simple high-pressure engine working without condensation. No im- mediate improvement in the duty seems, however, to have followed. 1811. —The first monthly report appeared of the duty of three engines at work at Wheal Alfred Mine, where Captain J. Davey was engineer. The great improvements indicated by the rapid increase of duty in the period to which we shall now refer have resulted mainly from the use of high-pressure steam worked expansively, and the introduction of Trevithick's Cornish boiler. 1813. —The first year in which the duty papers appeared in their present

form ; the number of engines reported was 24, of which the average duty was 19,456,000 foot lbs. In the early part of the year the best duty was about 26 millions, by Captain Trevithick at Wheal Prosper, Captain John Davey at Wheal Alfred, and Messrs Jeffery & Gribble at Stray Park. Towards the close of the year Davey first attained 2V millions, and Jeffery & Gribble reached 28 millions.*

1814. —Number of engines reported, 29 ; average duty, 20,534,232. During this year Jeffery & Cribble's engine at Stray Park

performed the best duty, having reached 35 millions ; for twelve months the average was 32 millions. WooU's engine at Wheal Abraham, first reported in October of this year, performed 34 millions. 1815. —Number of engines reported, 35; average duty, 20,526,110. Woolf's engine at Wheal Abraham attained a duty of 5 2 '3 millions. 1816. —Number of engines reported, 32; average duty, 22,907,110. In

* The duty was calculated per bushel of 94 lbs. of coal up to July 1856 ; after tliat date the cwt. was substituted for the bushel. 24 PUMPING MACHINERY.

this year an engine at Dolooath, by Messrs Jeffery & Gribble,

did a duty of 40 millions, which is the first record of such a duty done by a single-cylinder engine. In May of this year Woolf's engine at Wheal Abraham did a duty of nearly 57 million

1817. — Number of engines reported, 31 ; average duty, 26,500,259. The general improvement was now beginning to be apparent, as may be observed from the average of this and the preceding year. JefFery & Gribble continued to take the lead, and their engine at Dolcoath in some months reached 44 millions. Woolf's engine occasionally surpassed this, reaching to 51 and 52 millions, but

after this year it did not exceed the average of the best single engines.

1818.—Number of engines reported, 32 ; average duty, 25,433,783. No improvement in this year, and the general rate of duty rather

fell off. 1819. —Number of engines reported, 37 ; average duty, 26,252,620.

1820. —Number of engines reported, 37 ; average duty, 28,736,398. Among these were the engines lately erected at the Consoli- dated Mines, by Woolf, having cylinders of 90 in. diameter, and a

stroke of 10 ft., the most powerful that had been constructed. 1821. —Number of engines reported, 39; average dutj', 28,223,382. 1822.— „ „ „ 45; „ 28,887,216. 1823.— „ „ „ 45; „ 28,156,162. 1824.— „ „ „ 45; „ 28,326,140. The best duty seems to have been done by Sims' engine. 1825. —Number of engines reported, 50; average duty, 32,000,741. General improvement was now observable. Sims' engine at Polgooth reached nearly 54 millions, and some new engines appeared in the first rank of merit, as those by Woolf, at Wheal Alfred and Wheal Sparnon, by Webb at Herland, and by Grose at Wheal Hope. This latter engine deserves the more notice, as it was the first erected by this engineer, and its construc- tion led to the great improvements in duty which he afterwards exhibited in his engines at Wheal Towan.

1826. —Number of engines reported, 48 ; average dlity, 30,486,630. 1827.— „ „ „ 48; „ 32,100,000. Although the average duty of all the engines in the county was not so much improved in this year as might be expected from the results exhibited by the performances in particular instances, yet this must be deemed an important epoch in the history of the steam-engine. One which had been erected by Grose, at

Wheal Towan, of 80 in. cylinder, in which he had perfected all ho had tried in his engine at Wheal Hope, was found to surpass all others for the first nine months of the year, and from April EARLY HISTORY OF PUMPING-ENGINES. 25

to September maintained a duty of more than 60 millions, reaching in the month of July to more than 62 millions. 1828.—Number of engines reported, 54; average duty, 37,000,000. Public attention having now been directed in Cornwall to the improvements which Grose had introduced, and the principles being applied with various modifications in many instances, the advantage was rendered obvious by the advance in the average duty of the whole. And in the meantime the engine at Wheal Towan was brought to a degree of perfection which had not been anticipated by the most sanguine, advancing in March to

more than 80 millions, a rate of duty which it maintained, with some fluctuations, to the end of the year.

5.3 1829. —Number of engines reported, ; average duty, 41,700,000. 1830.— „ „ „ 56; „ 43,300,000. 1831.— „ , „ 58; „ 43,400,000. 1832.— „ „ „ 59; „ 45,500,000. 1833.— „ „ „ 56; „ 46,600,000. 1834.— „ „ „ 52; „ 47,800,000. During the year 1834 several engines were reported to do remarkable duty, notably West's engine at Fowey Consols and Taylor's engine at the

United mines ; the former was said to do a duty of 125 millions on 94 lbs. of coal, and the latter 107 millions. The author has indicator diagrams from both engines in his possession, and they show initial pressures of 50 and 36 lbs. absolute respectively, the expansion in both cases being a little over 4 to 1. If the above reported duty were correct, the Fowcy Consols engine would have given at least an indicated H.P. per hour on 12 lbs. of feed water and Taylor's engine on 15-2 lbs.,* which is in the former case impossible.

Since 1834 little progress has been made in Cornwall ; the best engines have done about 60 millions duty, and, according to the records, in exceptional cases much higher, but of late years the recorded duty has fallen off, and there are but few engines at work in the county. We have been induced to devote some considerable space to the pro- gress of the Cornish engine, for it was with that engine that the principles governing steam-engine economy were first practically grappled with. The progress which has been made since has been great, but the possibility of advance has been aflbrded by the improvements in manufacturing pro- cesses and materials, by means of which we can safely use high-pressure steam.

In the early days of the development of the pumping-engine it became recognised that economy was to be secured by expansion, and it soon became known from the teaching of experience that considerable expansion could be secured in the single-cylinder Cornish engine. As a matter of fact, the single-cylinder Cornish engine was quite

* Assuming an evaporation of 10 lbs. of water jier 1 lb. of coal, and a mechanical efficiency of tlie engine and pumps combined, of 80 per cent. 26 PUMPING MACHINERY.

capable of getting the best duty from steam of the pressure used. Attempts were, however, made by Hornblower, Trevithiok, Woolf, Sims, and others to secure greater economy by the use of compound engines. Many compound engines were made, but the duty obtained was no better than that obtained with the single cylinder. The method of expanding in the compound engine was simply that of allowing the steam to expand from the small cylinder into the large cylinder. The total range of expan- sion was not more than in the single engine.

In figs. 5 and 6, sections of Hornblower and Trevithick's and also of Sims' engines are given. Neither the distribution of steam nor the boiler

Fig. 5. Fig. 6.

HOBNBLOWER AND TRE.VITHICKS COMPOUND CORNISH ENGINE SIMSS COMPOUND CORNISH ENGINE.

pressure available were conducive to economy in the compound engine.

It is only quite recently that the development of the Cornish engine has advanced by the adoption of a second cylinder. From Watt's time—1800 to 1834 —the boiler pressure was raised from 10 to 45 lbs., and the duty trebled; since 1834 the safe boiler pressure has been raised from 45 lbs. to 200 lbs., and the duty of our best pumping-engines nearly doubled. We have not space to trace further the history of the development of the pumping-engine. The practicability of making boilers to be worked with high-pressure steam and the new and extended requirements of modern times have led to the production of new forms of engines and pumps, many of which are noticed in the succeeding chapters of this book.

Note. —The duty of pumping-engines is now generally calculated on 112 lbs. of coal. Previous to 1856 it was expressed per bushel of 9i lbs. In Savery's and Sineatou's time the bushel was evidently taken to be 84 lbs.

PLATE /r.] [Til fare piiije 27.

A'^loii I'umping Slatimi, C\iy of Biriiiingliam Waterworks. OHAPTEE II.

STEAM ENGINES (PUMPING).

As the steam engine plays so important a part in connection with pumping

machinery, it will be well to devote this chapter to a consideration of the

principles which govern and limit its application. It will have been observed from the brief and incomplete history

contained in the first chapter that it was as a pumping-engine that the

steam engine as a practicable machine received its first application, and

that the general principles which govern its economy were first grappled with in those engines. The greatest economy has always been obtained

with pumping-engines, and it is so at the present day. We need not consider the subject of quick reciprocating engines, because such engines have a limited application to pumping purposes. They are useful and convenient for driving centrifugal pumps direct, but for general pumping they are little used.* It may, however, be observed, that although certain economical conditions are secured by quick reciprocation, no quick reciprocating engine has been found to be so economical in steam as the slow-running pumping-engine.

It is the common experience that the quicker an engine runs within

the limits of its application, the better should be its economy in steam,

but that is only true when comparing the conditions of running of the particular engine or engines of its class. It is not true as a generalisation that quick-running engines are more economical in steam than slow- moving ones. There are many factors which enter into the question of steam economy.

Fig. 7 is a diagram in which the curves are not true curves ; they are used for illustrative purposes only. A perfect steam engine, according to Kankine and others, was defined to be an engine working without loss, receiving the steam at the higher temperature and expanding it adiabatically to the lower temperature.

Let A (fig. 7) represent an indicator diagram, the upper line above it

* Professor Riedler has produced a, quick reciprocating pump for quick-running

engines ; it is described in the chapter on pumps.

27 —

28 PUMPING MACHINERY.

representing the adiabatic curve for the weight of steam admitted to the cyUnder. Then the losses arise

a. From condensation in the cyhnder.

b. Clearance.

e. Back pressure.

(L Incomplete expansion.

The loss a is reduced by steam jacketing and superheating. By

steam jacketing, cylinder condensation is reduced, but experience has shown that in jacketing the cylinders alone a less percentage of economy

is obtained in a modem economical triple compound engine than that secured in ordinary compound or single-cylinder engines.

The efficiency of the steam jacket is also influenced by the quality of

the steam from the boiler. If water is admitted with the steam either by priming or from condensation in the steam pipes, then the steam jacket

Fig. 7, —Diagram of Steam Engine Losses.

has additional work to do in evaporating the water deposited on the

surfaces by what is badly named ' wet steam.' Superheating may be effected by utilising the waste heat from the

furnace gases, or by means of superheaters placed in the boiler flues. In the latter case the superheat may be obtained at the expense of boiler heat.

Superheat is readily dissipated by radiation from long lengths of steam pipe.

Superheating, or adding heat, is also done by introducing super-heaters, consisting of coils of pipe filled with steam at boiler pressure, into the receivers between the cylinders of compound engines. The loss from cylinder condensation is greater than that indicated by

the shaded part a (fig 7), because without condensation the expansion

might be carried further, and the loss from incomplete expansion, d, thereby reduced—that is to say, the indicator diagram, if coinciding with the upper liuo of the diagram might be extended till the terminal pressure STEAM ENGINES (PUMPING). 29

was only equal to the pressure required to overcome the frictional resistance of the engine, which may be assumed, for illustration, to be the terminal pressure of the diagram A. Ee-evaporation takes place in the cylinder, because, during admission, the cylinder walls are receiving

heat, and during expansion they are giving it out. If we assume, for the sake of illustration, that the re-evaporation was complete at the end of the stroke, and that the terminal pressure of the indicator diagram A coincided with the point e of the adiabatic curve, then the loss from cylinder condensation as compared with adiabatic expansion would be repre-

sented by the shaded portion a. Clearance (b). —The loss from clear-

ance spaces is sometimes considerable, especially in non-rotative engines, but when the non-rotative engine has a long stroke, the percentage loss may not be much greater than that of a short stroke rotative engine. Where

considerable clearance is necessary, as in non-rotative engines, the loss is reduced by cushioning, especially in the Cornish engine, in which the vis viva of the falling mass is taken up by the cushioning.

Cushioning is also used in a large degree in the author's varying lever engine described in Chap. XII., and shown in detail in fig. 185, Chap. X.

In rotative engines, experience is in favour of reducing the clearance spaces, for, whatever may be the merits of cushioning in its influence on economy, it is undesirable to employ J-'ig- 8. —Section of Steam Cylinder with

'^"''=' ^''1^<=' """^^^ f""^ reducing it in a large degree in pumping-engines ™

,, , , , „, clearance spaces. controlled by a crank. Clearance spaces may be reduced by putting the steam valves in the covers of the cylinders, as shown in fig 8. Here the valves are of the Corliss type, and are clearly indicated in section.

Back Pressure (c). —This loss is an important one, and demands attention, not only in the designing of the engine, but also in its daily working. Let the average pressure on the low-pressure cylinder be 20 lbs. per square inch. A back pressure of 1 lb. will represent 5 per cent. A condensing engine working with a vacuum of 20 inches of mercury instead of 26 inches may be losing 15 to 20 per cent, in economy. 30 PUMPING MACHINERY.

Condensers should be of ample capacity, and be provided with every facility for cleaning and repairs. We have heard it argued that a con- denser is not part of a steam engine, but it is a good practical rule to look upon a steam engine with a bad condenser as a bad condensing engine. iDComplete Expansion (d). —The loss from incomplete expansion may be looked at in two ways. Practically, there is no use in continuing the expansion beyond the point at which the terminal pressure of the indicator diagram is no more than that required to overcome the useless resistances of the engine. Theoretically, the loss is represented by the space bounded by the adiabatic curve beyond the point e (fig. 7), and the bottom line or line of no pressure. Practically, there must be back pressure, and the most perfect condensing engines in use have a back pressure of about 1 lb. absolute, corresponding to about 100° F. In calculating the theoretical work for a given weight of steam, it is usual to calculate from the limits of temperat\ire, and as 100° F. is the lower practical limit for the most perfect condensing engines, that temperature will be adopted by the author. The loss from incomplete expansion is, then, that represented by the area bounded by the adiabatic curve beyond e, and the bottom line representing about 1 lb. back pressure or 100° F. We shall see, further on, that the most economical condensing engines of to-day, compared with a theoretically perfect steam engine using saturated steam, give an efficiency ratio of over 60 per cent., so that the total of the losses which we have enumerated is under 40 per cent. It must be observed that by carrying expansion further the loss from incomplete expansion may be reduced, but the mechanical efficiency of the engine may, at the same time, be reduced ; for not only may the friction be increased by the larger engine, but, as the mean pressure is re- duced, the friction becomes a larger percentage of the total indicated power. The indicator diagram, with all its defects, is the measure of the I.H.P. which forms the basis for scientific piirposes of investigation or of comparison of different types of engines. It is therefore important that the diagram should be analysed as to the losses indicated in fig. 7, other- wise false conclusions may be arrived at. For practical purposes the thermal units expended for the work done is the important result, but the losses as shown by an analysis of the indi- cator diagrams should not be ignored, because the result, good or bad, may have been greatly influenced, not by defects in the engine itself, but by the circumstances under which it was working. Priming and Steam Pipe Radiation. —Engines are very seldom sup- plied with dry steam. Proper precautions should be taken to drain off the water from the steam pipe. This should be done quite close to the stop valve by means of automatic steam separators. Insufficient attention is given to this matter, which is of great importance as affecting the economy of the engine. Steam pipes should not be unnecessarily large or long, and should be thoroughly well covered to prevent radiation. — 1

STEAM ENGINES (PUMPING). 3

Frictional Losses. —It is usual to express this loss in percentages of the I.H.P. of the engine. The mechanical efficiency of an engine is said to be

70, 80, or 90 per cent., as found in the engine trial, but it is useful to know how many lbs. pressure per sq. inch of the piston that represents, for it is obvious that, within limits, the heavier the load on the engine, or the greater the mean pressure, the less may be the percentage of loss from friction. To obtain the greatest economy per I.H.P., it may be necessary in a particular case to work the engine with a low mean pressure, the frictional resistance forming a large percentage of the total I.H.P. The true economy is not expressed in terms of I.H.P., but in pump H.P., or, including the pump H.P., in the quantity of water pumped or what may be termed water H.P. Non-rotative engines have generally the advantage in mechanical efficiency, but rotative engines of the most approved designs, suitably applied, are superior in economy per I.H.P. Geared engines have a low mechanical efficiency. Leakage.—The question of leakage through valves and pistons is one of great importance, as an engine of superior design may fail in economy from that cause alone. Good workmanship in the working parts is of more vital importance than polished columns, although we may here remark that a well- finished engine receives more care from its attendant than does a less sightly machine. Standard of Comparison.—One steam engine may be shown to be better than another by its using less saturated steam per I.H.P. per hour

or by its producing a greater number of work units per heat units

expended. The thermal efficiency of the engine is thus expressed :

heat utilised . Thermal efficiency = r i r^^i •' heat— supplied

foot lbs. of work done '°' units of heat supplied x 778'

778 being the recognised equivalent in foot lbs. of one British thermal unit. The efficiency of engines thus expressed enables one to compare their relative economy, but as higher pressures possess greater possi-

bilities of economy, and engines may be condensing or non-condensing, we require a standard of comparison which shall be applicable to the conditions under which the engine works, whereby we may be able to

judge how far it has been advanced towards perfection. The true standard

is the ideal perfect steam engine—an engine taking steam at the higher pressure and expanding it adiabatically to the lower or exhaust pressure

without loss. The formula for such an engine was determined by Rankine. The B.T.U. per H.P. for the standard engine of comparison can be calculated by means of the formulae which follow. — — — —

32 PUMPING MACHINERY.

The formula for the thermal efficiency of the Rankine cycle for saturated steam is

(Ta-T.)(l+g)-T.hyplogg, » La + Ta^fe in which formula the increase in the specific heat of water at higher tem- peratures affects the numerator and denominator nearly equally. The B.T.U. per minute per H.P. for the standard engine of comparison is 42-4, divided by the thermal efficiency of the Eankine cycle thus : For saturated steam, the B.T.U. per minute per H.P. for the standard engine of comparison is : 42-4(L6t + Ta-Te) (Ta-T.)(i+gj-T.hyplogg'

and similarly for superheated steam it is : 42-4|La + Ta-Te + 0-48(Tas-Ta)} (T«-T«)(^l + ^j + 0-48(Tas-T«)-Te(^hyplog^ + 0-48hyplog^'j

The meanings of the letters used in the above formulce are :

Ta = absolute temperature of saturated steam at stop-valve pressure. Tas = absolute temperature of superheated steam at stop-valve. Te = absolute temperature in exhaust. La = latent heat of steam at temperature Ta.

As tliese formulae are somewhat difficult and tedious to work out, use is made of the <(> chart, and for practical purposes when great accuracy is not required the author uses a simple approximation. It will be observed that the leading factors are the higher temperature

Ta and the lower temperature Te ; the former that of the steam entering the engine, and the latter that of the steam leaving it.

Ta = temperature of steam at inlet. T« = temperature of steam in exhaust at outlet. The engine may be condensing or non-condensing. In pumping-engine practice the value of Te may be taken. T« = 212° nou-eondensing. Te = 100° condensing.

The rational minimum lower temperature Te of the condenser for the perfect engine would appear to be the mean teriperature of the atmos- phere, 60°, but condensers must have a back pressure, and that corre- sponding to 100° Fahr., or say 1 lb. pressure, is a good working standard. If we take as a standard 100° as the lower temperature for condensing engines and 212° Fahr. (or that corresponding with the atmospheric pres- sure) for non-condensing engines, we may construct a very simple and useful approximate formula which will enable us to compare the perform- ance of an actual engine with that theoretically possible, without the use of the Rankine formula.

* "Thermal Efficiency Report," Proceedings Inst. C.E., 1898. . — —

STEAM ENGINES (PUMPING). 33

The following empirical formula is only applicable to saturated steam :

Let L = lbs. of steam per I.H.P. per hour.

T = the higher and t the lower temperatures.

For condensing engines let t = 100°, and for non-condensing engines let it be 212°.

Then approximately in the theoretically perfect engine the lbs. of steam required per I.H.P. per hour would be for condensing engines

2540 , , . . 2540 ~- == , for non-condensmg engines ——— T-40' *^ ^ T-192 This formula should only be used for pressures between 30 and 200 lbs. absolute ; but within these limits the errors are very small, as will be seen from the table below. The following table gives the theoretical values according to the

Rankine formula and the author's approximation :

Condensing Engine's Exhaust 34 PUMPING MACHINERY.

Tlie nearer the theoretical standard approaches to the actual conditions of the steam engine, the more useful will it be in showing the defects or perfections of one engine as compared with another.

For practical use we have constructed diagrams (figs. 9 and 10) show- ing at a glance the theoretical weights of feed water per I.H.P. per hour STEAM ENGINES (PUMPING). 35 approached in practice. It will be observed that the ideal engine expands the steam adiabatically down to the back pressure of the condenser, but actual engines do not usually expand the steam to a lower pressure than 10 lbs. absolute.

With engines working in the Cornish cycle of steam distribution, it is — — ;

2,6 PUMPING MACHINERY.

exhausting it at 100° Fahr., requires 7"5 lbs. of steam per I.H.P. per hour. If the actual engine has been found to use 12 lbs. of steam under the same conditions as to initial and exhaust temperatures, then the efficiency 7.5 ratio = — = 625 per^ cent. 12

In other words, the actual engine performance is 62'5 per cent, of that of a perfect steam engine using saturated steam without loss. The number of thermal units per I.H.P. per hour expresses the economy of the engine, irrespective of steam pressure employed, but the eESciency ratio expresses the economy, taking the steam pressure into consideration. Having a given steam pressure, and knowing the weight of steam per I.H.P. per hour used by the engine, the question arises—Is the engine a good or a bad one 1 The efficiency ratio gives the answer at once and if we know the best efficiency ratio which has been obtained with engines of that type, we at once know how far the engine in question departs from the best practice. In this respect the efficiency ratio will be found to be of great practical use. To take an example. A triple expansion pumping-engine may have been found to give in working one I.H.P. per minute for 230 heat units. That may be considered a bad result as compared with another engine of the same type, but the two engines compared may have worked with different initial pressures, and the efficiency ratios may have been the same in both cases. The potential of the steam is taken into consideration in the efficiency ratio, just as the evaporative efficiency of the boiler and coal must enter into the calculation if we wish to estimate the relative economy of the engines from the coal consumption. Practical Use of the Ratio. —If we refer to the table on page 37 it will be seen that the best efficiency ratios of the practical examples given for the different types of engines are approximately

Condensing Engines.

Cornish, single acting, . . .60 per cent.

Single cylinder, double acting, . 45 ,,

Compound double acting, . . 55 ,,

Triple compound double acting, . . . 60 to 65 ,,

In the Table we have not been able to distinguish in all cases between the trials which give results in lbs. of feed wafer, and those which give lbs. of dry steam. The Cornish and marine examples of many of the others are expressed in lbs. of feed water, whilst the triple pumping-engine examples give lbs. of steam.

If all the trials were on the same footing in lbs. of steam, the efficiency ratios of the best examples would probably be represented approximately thus :

Cornish, single acting, . . . .65 per cent.

Single cylinder, double acting, . . . 45 ,,

Compound double acting, . . . . 55 ,,

Triple compound doiible acting, , , . 65 ,, STEAM ENGINES (PUMPING). ii

These figures must not be taken as standards of practical perfection, but if the best results are thus tabulated, a standard of comparison for each type of engine may be found ; and any engine giving a lower efficiency may be said to fall short of the best modern practice. The following tables contain the results of selected engine trials, and a column giving the efficiency ratio in each case.

Steam Engine Trials. 38 PUMPING MACHINERY.

References to Trials.

Eeference Numbers.

Steam-jacket Research Committee, Inst. Meoh. Engs. (2nd Report). Trial by Prof. Unwin. Ditto. 2 Trial by Mr Henry Davey of Engine at the Wolverhampton Waterworks. 3 Research Committee on Marine Engine Trials, Inst. Mech. Engs. (Pro- ceedings, 1890). Trials by Dr Kennedy. 4 Ditto. 6 Ditto. (Proceedings, 1892.) 6 Steam-jacket Research Committee, Inst. Mech. Engs. (3rd Report). Trials by Mr Bryan Donkin. 6a Ditto. 7 Steam-jacket Research Committee, Inst. Mech. Engs. (2nd Report). Trial by Prof. Unwin. 7a Ditto. Steam-jacket Research Committee, Inst. Mech. Engs. (3rd Report). Trial by Prof. Beare. 8a Ditto. Steam-jacket Research Committee, Inst. Mech. Engs. (3rd Report). Trial by Mr Bryan Donkin. 9a Ditto. 10 Steam-jacket Research Committee, Inst. Mech. Engs. (2nd Report). Trial by Mr Mair-Eumley. 10a Ditto. 12 Research Committee on Marine Engine Trials, Inst. Mech. Engs. (1890). Trials by Dr Kennedy. 13 Ditto. (1889.) 15 Steam-jacket Research Committee, Inst. Mech. Engs., East London Water- works (3rd Report). Trial by Messrs Beare, Donkin and Davey. 15a Ditto. 16 Trial by Prof. R. H. Thurston. 17 Steam-jacket Eesearch Committee, Inst. Mech. Engs., East London Water- works. Trial by Messrs Beare, Donkin and Davey. 17a Ditto. 18 Steam-jacket Research Committee, Inst. Mech. Engs. (2nd Report). Trial by Mr Henry Davey. 18a Ditto. 19 Research Committee on Marine Engine Trials, Inst. Mech. Engs. (1891). Trial by Dr Kennedy. 52 Clark's Steam Engine, vol. ii. p. 509, East London Waterworks. Trial by Mr C. Greaves. 53 Ditto. 5i Ditto. 65 Ditto. 56 Trial by Dr Kennedy, The Engineer, 29th August 1890. 57 Trial by Prof. Unwin of Engines at West Middlesex Waterworks. Engineer- ing, 7tli December 1888. 58 Trial by Mr J. W. Hill, Cincinnati. Clark's Sttum Engine, vol. ii. p. 516. 69 Ditto. 60 Ditto.

Cost of Motive Power. —The motive-power engines employed to work pumps may be steam, water, gas, or oil engines, and the application of the power may be made direct or not ; by transmission electrically (with or without gearing) ; or by means of water or air pressure. The choice of the motive power and the mode of its application should be governed by considerations of adaptability, economy, and convenience. It is sometimes commercially expedient to employ a system or power that is uneconomical —

STEAM ENGINES (PUMPING). 39 in fuel. Where the power to be applied is small, it often happens that the cost of fuel alone is of smaller importance than other matters. There is no general rule that can be applied, and without looking at the question in all its bearings from a practical and commercial point of view, false conclusions may be the result. Efficiencies, thermal and mechanical, should be inquired into, but the argument is not complete that does not lead up to the commercial efficiency, or the least expensive way of doing the work, taking all matters of expenditure and convenience into consideration. It is difficult to state in a book all that is necessary for a complete judgment in this matter.

Where the power to be applied is very large the cost of fuel is one of the most important, and sometimes the most important, consideration, and in this connection the fuel per indicated horse power and the thermal efficiency are as misleading, if taken alone, as the old and now happily obsolete term "nominal horse power."

Where the power is applied direct in, say, a water motor, then the the mechanical efficiency of the machine determines useful power available ; but when we come to compare the consumption of fuel iu steam, gas, and electric plants, we have a multiplication of efficiencies to deal with. We will proceed to make the comparison in a simple way.

1 horse power = 33,000 foot lbs. per minute. .-.1 ,, =1,980,000 ,, per hour.

One British thermal unit of heat = 778 foot lbs. The thermal equivalent,

' then, of one horsepower per hour= ' — =2545 British thermal units:

written 2545 B.T.U.

_, „ , , , B.T.U. per horse power per hour. per hour = Lbs. of coal horse power per ^ K^ -,-, r: , . B.T.U. per lb. of coal.

Assuming 1 lb. of coal to have a thermal value of 13,000 B.T.U., then we have the theoretical value of one horse power in lbs. of coal

= ^5i^=-19 1b. 13,000 The thermal efficiency of a steam engine and boiler combined, using

1-9 lbs. of coal per horse power per hour, is then 10 per cent. These figures will assist us in the following argument. Steam Plant —The thermal efficiency of a well-designed boiler plant may be estimated at 70 per cent., and that of the engine 15 per cent. The mechanical efficiency of the engine may be 90 per cent. The total efficiency in work done at the engine-shaft will then be :

70% X 15% X 90% = 9-45%.

Taking the thermal value of the coal at 13,000 British thermal units — — —

40 PUMPING MACHINERY. for one lb. of coal, the thermal equivalent of the work done at the engine-shaft in B.T.U. will be, per lb. of coal : 18,000 X 9-45 % = 1228 B.T.U. 2545 And the coal per actual horse-power hour = 2 lbs. ^1228 Gas Plant. —The total thermal efficiency of the gas producer may be taken as 60 per cent., that of the engine 25 per cent., and the mechanical efficiency of the engine 80 per cent. The resultant efficiency will then be :

60 % X 25 % X 80 % = 12 %. Taking the same thermal value for the coal as before, we have as the thermal value for the work done at the engine shaft ; 13,000 X 12 % = 1560 B.T.U. 2545 The lbs. of coal per actual horse power will be = 16 lbs.

The foregoing calculations may be taken to be a fair comparison for large engines when the steam engine is a first-class condensing engine, and the gas engine a first-class one with its own producer. In applying such engines to work pumps, the steam engine may be used direct, but the gas engine requires gearing. The loss of effect in the gearing may more than counterbalance the superior efficiency at the gas-engine shaft, so that the net effect in water raised is in favour of the steam engine. Taking coal, having a thermal value of 13,000 B.T.U. as before, at sixpence per cwt., we get from the gas producer 13,000 x 60 per cent. = 7800 B.T.U. per lb. of coal, or 7800x112 = 873,600 B.T.U. for sixpence. If the producer gas has a calorific value of 120 B.T.U. per cubic foot, and is sold for working pumps of a large size and power, it must be supplied at a rate of 7280 cubic feet for sixpence to compete with steam for pumping purposes on a large scale. It will be seen from the foregoing calculations that gas cannot well compete with steam, where the steam engine is applied direct and the gas engine is applied through gearing. As a matter of fact the gas producer, at present, requires more expensive fuel than the steam boiler; but for driving machinery the gas engine and producer are entering into competition with the steam engine and boiler. Draining Mines. —Both gas and steam plant with electric transmission of power have been proposed for draining mines, with the idea of dis- pensing with the use of pump-rods in the shafts. Steam power with electric transmission has been carried out with plants of considerable power, illustrations of which will be given further on. The mechanical losses in applying electric transmission to the working of pumps in a mine underground may be thus estimated :^

Mechanical ^jfficiencies.

Dynamo, ...... 90 per cent.

Line, etc., . . . . . -90 ,,

Motor, ...... 85 ,, : 1

STEAM ENGINES (PUMPING). 4

The mechanical efficiency of the electric transmission of the power alone

is then 69 per cent. The power may be applied to the working of plunger pumps by means of gearing, by direct driving from a slow-speed motor, or the motor may be applied direct to the spindle of a high-lift centrifugal pump. The mechanical efficiency of the three systems may be for the puTnps alone —

Direct driving from a low-speed motor, say 150 revolutions, 80 per cent.

Pumps driven through gearing, . . . . 70 ,,

Centrifugal high-lift pumps, . . . 60 „

We then have as a total mechanical ef&ciency where centrifugal pumps

are used, say, 35 per cent. ; and the coal per pump horse-power hour will

be, with coal of 13,000 B.T.U. value, 2545 divided by 330, which is practically 7'7. A pumping-engine working spear-rod pumps direct may have a thermal efficiency of 15 per cent., and a mechanical efficiency of engine and pumps combined of 80 per cent. Taking the boiler efficiency as before, the E.T. U. utilised per pump horse power will be 1092, and 2545 the coal per pump horse-power hour = say 2 '4 lbs. There is then a large margin in favour of the direct application of steam power, and a steam engine of quite moderate thermal efficiency will compete with electric transmission. The above line of argument will enable a comparison to be made of different systems where the efficiencies differ from those assumed. It will

be seen that the cost of fuel is increased where electric transmission is adopted, because of the various losses in mechanical efficiencies ; but there are other questions of equal or more importance. When pumps are worked by means of gearing or are of the centrifugal type, the mechanical efficiency is small. For very small powers that loss of efficiency does not matter much, but for large powers it is serious.

As regards the centrifugal pump, this pump is now adapted to high lifts by putting two or more pumps in a series, either as separate pumps or combined in one casing. We have assumed a mechanical efficiency of 50 per cent, for this pump in our calculations, as our experience is that

50 per cent, is as much as is generally secured in practice. The maximum efficiency is only secured under critical conditions ; as a slight falling off in speed reduces the efficiency enormously, and in this respect compares very unfavourably with the plunger pump, the efficiency of which is but little affected even by large variations in speed. Efforts are being made to work plunger pumps direct from electric motors, examples of which will be found in another chapter. In the foregoing calculations we have not assumed the highest efficiencies which may be obtained in special trials, but such efficiencies as are consistent in practice and are fairly comparable. —

42 PUMPING MACHINERY.

Table showing the number of lbs. of saturated steam required per

I.H.P. per hour, with various steam pressures and efficiency ratios :

Condensing Engines, Lower Temperature 100° Fahr. STEAM ENGINES (PUMPING). 43 o a -^-^ 44 PUMPING MACHINERY.

No. 1. No. 6.

No. 2. No. 6.

No. 3. No. 7.

No. 4. No. 8.

Fig. 11. —Diagrams illustratiug the distribution of steam in various types of Pumping- Engines. STEAM ENGINES (PUMPING). 45 or more. Here, then, is the use of the ratio in discovering how imperfect an engine is of its type. Steam Distribution. —On the opposite page we illustrate by diagrams the different systems of steam distribution used in pumping-engines (fig. 1 1). No. 1 is that of the ordinary non-expansive single cylinder steam pump.

It is difficult to say what is the usual consumption of steam per H.P.

When non-condensing, it is probably 100 lbs. or more per pump H.P. per hour, but notwithstanding this wastefulness, such pumps have a commercial

value in the cheap and ready way in which they are applied to all sorts of temporary and, in fewer cases, permanent work. Considerable improve-

ment is obtained by compounding and condensing. The author has applied the single non-condensing steam pump in special cases in a way which has resulted in considerable economy of steam.

The system is explained by the following diagram (fig. 12). At the Whitacre pumping station of the Birmingham Water Works

there are two sets of steam boilers, one supplying steam at 70 lbs. pressure to the compound engines, and the other at 30 lbs. pressure supplying steam to the Cornish engines.

The low lift pumps for lifting the river water to the filter beds are of the simple duplex steam pump type, and are worked from the high-pressure boilers, exhausting into the low-pressure ones. At the Aston station of the Birmingham Water Works, where there

are six large low-pressure engines working with 20 lbs. boiler pressure,

it became necessary to increase the pumping power with a small capital

outlay, and the author adopted the system illustrated in fig. 13.

A large non-condensing compound steam pump (illustrated in fig. 236,

Chap. XIII.), capable of raising 3,000,000 gallons per day 250 ft. high, was erected, together with a battery of boilers having a working pressure of

130 lbs. The low-pressure engines were all connected to one low-pressure steam main, and the new steam pump was made to exhaust into the low-pressure

system ; in that way the low-pressure engines were supplied with steam largely from the exhaust of the compound steam pump.

No. 2, fig. 11, illustrates the distribution of steam in a single cylinder engine.

No. 3, fig. 11. Woolf compound engine, in which there is a cut-off

valve on the high-pressure cylinder only. In such engines there is gene-

rally a considerable drop in pressure between the cylinders, especially if the pistons move in the same direction, because then the steam port capacities become large.

No. 4, fig. 11. Seceivei- engine. That is a compound engine having a cut-off valve on both cylinders. A receiver between the cylinders becomes necessary, and the cut-off should be so arranged that the initial pressure in the low-pressure cylinder is about equal to the terminal pressure in the high-pressure cylinder. 46 PTTMPING MACHINERY. STEAM ENGINES (PUMPING). 47

«^ 48 PUMPING MACHINERY.

Cornish Cycle Ungines.

All tlie four systems of steam distribution admit of the Cornish cycle.

In No. 5, fig. 11, where there is no expansion, the steam is admitted to one side of the piston, and, after doing its work, is passed to the other BIRMINGHAM WATER WORKS.

AstoTv Statiorv.

«< Sieam.

A rrange^ment' of Cornish Engine' and- Feecly-waZer Heater

/e«

•*— To Gm/ienser '

14. Fig. —Arrangement of Feed-water Heater ; Aston Pumping Station. side of the piston to be discharged to the atmosphere or to a condenser on the next steam stroke.

No. 6, fig. 11, is a diagram of the ordinary Cornish engine distribu- tion. The limit of expansion in the ordinary Cornish engines is from three to four times. The engine is therefore worked with low-pressure steam.

No. 7, fig. 11, illustrates the distribution in a compound Cornish cycle engine— that is, an engine in which both the high- and low-pressure STEAM ENGINES (PtTMPING). 49

cylinders are single acting, both taking steam together, and both taking

the equilibrium stroke together. There is a cut-oflf in the high-pressure cylinder only.

No. 8, fig. 11, is from a similar engine having a cut-oiF in the low- pressure as well as in the high-pressure cylinder. The Cornish cycle admits of a system of heating feed water advan- tageously to a temperature above that of the exhaust steam. During

the equilibrium stroke of the engine the steam is but little below the

pressure of release, generally about 10 lbs. absolute or 194°. Now if a pipe having a non-return valve be taken from the equilibrium pipe of the

engine to a feed-water heater, as shown in fig. 14, the feed water will be heated advantageously to a temperature far above that of the exhaust

(100°) by steam which has done its work, but which is retained in the cylinder during the equilibrium stroke. The feed heater shown on previous page was applied to a Boulton &

Watt engine from which the diagrams fig. 1 5 were taken.

Indtcaiar J>iet^ams.

Fig. 15. — Indicator Diagrams.

It will be seen that the equilibrium steam happened to be at about atmospheric pressure.

Other applications of the system are shown in figs. 16 and 17. Fig. 17 illustrates the construction of a condensing steam pump working without expansion, and heating the feed water to a very high temperature. Let the steam pressure be 100 lbs. per square inch, equal to 328° Fahr.

During the equilibrium stroke the pressure might fall to say 80 lbs., equal to 312° Fahr.

On the opening of the exhaust valve, the exhaust steam would fall to say 100° Fahr. ; that steam would pass through the first section, A, of the feed heater. During the equilibrium stroke some of the equilibrium steam would pass into B, the second section of the heater, raising the temperature of the water to say 300° Fahr.

Fig. 16 illustrates one pair of cylinders of a double-acting Cornish cycle rotative engine having cranks opposite each other. Steam is admitted 4 so PUMPING MACHINERY. and expanded above the top piston, then it is passed to the bottom side, where there might be placed a coil constituting a superheater. The steam from there passes during the next steam stroke to the top of the bottom piston : from there it passes during the up stroke to the under side of the piston to be discharged through the heater A to the condenser on the down stroke.

The down stroke is the steam and exhaust stroke, and the up the

Fig. 16. Pre. 17.

ffl

G^, ^Superheater

Condenser

Steam Distribution

D Steam Distribution

Distribution of Steam. Heaters.

equilibrium stroke. This engine may be worked on the receiver system of steam distribution as indicated by the diagram E, and the feed-water heaters applied as shown. The engine is made %ouble-aoting by having two pairs of cylinders like those shown in the illustration with the pistons connected to cranks opposite to each other. This form of engine has the advantage of having no lifting strain on the cranks, so that it may be run with loose bearings, the wear being always in one direction, and the bearings free from knock. CHAPTER III

PUMPS AND PUMP VALVES.

Types of Pumps.—The following illustrations of pumps are mere diagrams showing the peculiarities and characteristics of different types.

Bucket Pump, No. 1 (fig. 18). — This is the ordinary form of bucket pump. It consists of a hollow piston provided with a valve, the com- bination being called a 'bucket.' Below the bucket is a valve called a 'foot' or 'retaining valve,' commonly called a 'clack'; below the foot valve is the suction or supply pipe, and above the bucket is the rising main or delivery pipe. This pump may have an open top, the delivery of the water taking place over the top of the rising main, or the top may be closed by a cover having a stuffing box through which the rod passes. The water is then delivered through a branch in the rising main, from which a pipe may be taken in ^ any direction.

The common house pump is of this type ; when open topped it is called a 'lift pump,' but when the top is closed and the water is forced to a cistern above the pump, it is then called a ' force pump ; but the general and proper distinction between ' lift and force pumps is that bucket pumps of all kinds are lift pumps, and plunger pumps force pumps. When the plunger is combined with the bucket, it is called a 'lift and force pump.' '^^^ In the larger applications of the bucket pump it is called ^^"^ ^<^^^^ a 'bucket lift,' meaning that the water is lifted on the bucket in contradistinction to its being forced by a plunger or piston. In the bucket pump the total work in pumping the water is done on the up or lifting stroke, for that is both the suction and the delivery stroke ; the return or downward stroke is ' idle,' no work being done, and the bucket simply passes through the water to take its position for the next active stroke. The work is nearly all done on the up stroke, the resistance to the downward stroke is simply the friction of the bucket and the resistance of the water in passing through the bucket. This was the earliest form of mine pump worked by the Newcomen and Watt engines. It suited the 52 PUMPING MACHINERY.

engines in being single acting, and was attached to the outer end of the engine beam whilst the steam piston was attached to the inner end. The unbalanced weight of the pump rods overcame the friction of the engine and pump on the down stroke, but the down stroke was a source

of accident from what is termed a 'riding column.' Assume that the pump has been working properly and that the rising main or pump above the bucket is full of water, and that the bucket

makes an up stroke without taking in any water below it, either from the failure of water supply or from an air leak in the pump below the bucket, then on the commencement of the down stroke the bucket will be forced down not only by the unbalanced weight of the pump rods, but by the addition of the full water load on the bucket, which in the case of large pumps may be 10 to 20 tons or more. Such a weight falling freely through only a few

feet is a serious matter as regards the safety of the plant. This lA and other questions affecting the safety of pumps will be dealt with in other chapters. We have seen that this bucket pump

is entirely single acting.

Bucket Pump, No. 2 (fig. 19). —It is obvious that if two bucket pumps are employed, one making the up stroke whilst the other

Fig. 19. makes the down stroke, then double action is secured, and such Bucket arrangement is admissible where sufficient space is available, but Pump. it often happens that pumps have to be put in very confined

spaces, such as bore holes, and then it is important to get the greatest

delivery from a given sized pump. The pump now under notice is made double acting by placing two buckets in the same pump barrel, one below the other. To insure the double action

one bucket must be going up whilst the other is going

down ; the buckets must therefore have separate rods ; this

is usually accomplished by making the rod of the upper bucket a tube through which the rod of the lower bucket passes. A little reasoning on the action of the two buckets thus actuated will enable one to see that a foot valve

is not required and that we really have a double-acting pump with only two valves, one on each bucket. It will be seen that during the down strok^ of the bottom bucket (which takes place simultaneously with

the up stroke of the top bucket) water equal to the full Fig. 20. displacement of the double stroke is taken through the Plunger Pump. bottom bucket valve, so that the speed of water through this valve is double that through the valves of an ordinary bucket pump, and the speed through the upper bucket is the same as through the lower one.

Plunger Pump. —The ordinary plunger pump is indicated in fig. 20. In this pump the displacement of the water is by means of a rod or plunger A working in a barrel provided with suction and delivery valves. PUMPS AND PUMP VALVES. 53

B and E. The work done on the suction side is accomplished during the up strolte, whilst that of the delivery is effected during the down stroke. One of the advantages of this type of pump over the bucket or piston type is that the packing of the plunger can be applied from the outside, and the superior form of packing makes the pump suitable for greater columns or pressures of water than are possible with buckets. As the work done on the delivery stroke is generally, with this pump, immensely greater than that done on the suction stroke, the pump plunger is chiefly under com- pression strain, and when applied to mining purposes, it is expedient to make the weight of the pump rods above the plunger sufficient to over- come the resistance to the plunger on the down stroke. On the up stroke the work done by the engine is that of lifting the weight of the plunger and rods, and overcoming the resistance of the column on the suction side of the pump. The height of the suction column

is that from the level of the water to the top of the plunger barrel. We have already noticed in the history of the pumping- engine that the introduction of this type of pump changed the character of the Boulton & Watt engine, and constituted it the Cornish engine for reasons explained elsewhere. This

pump in its various modifications is applied to almost all purposes where very high pressures have to be dealt with.

The packing of the plunger is simple enough for almost any pressure in practice. There are many kinds of packing made, but a hemp 'gasket,' plaited square, and steeped in boiling

is as valves tallow, almost as good anythmg. The are of pjyjjggj.pmjjp various kinds, governed by the speed of the pump, the pressure, the state or nature of the water, and other practical considerations. This remark applies to all other pumps. Bucket and Plunger Pumps (fig. 21). —This is a combination of the two types of pumps already noticed, and its action will be readily understood

from the figure. This pump is double acting on the delivery, and single

acting on the suction side. The area of the plunger A is usually half

that of the bucket B ; in that case the work done on each stroke is not equal, because all the work of the suction side is done on the up stroke. It has been observed in the working of this pump, as also in the bucket pump, that when (in exceptional cases) the suction pipe is of considerable length, and the height to which the water is pumped is small, that the pump when driven fast may deliver more water than is accounted for by the displacement of the bucket. This is interesting and is worth notice. The reason may be thus given. The suction pipe, having no air vessel connected to it, contains a body of water which is put into motion by the action of the bucket, and if the weight and velocity of the water are sufficient, the momentum will keep the water in motion after the bucket 54 PUMPING MACHINERY. has completed its suction stroke and is making the return stroke. A fuller explanation will make this clear.

Let the suction pipe be 100 ft. long with a capacity of 1 gallon or

10 lbs. per foot, and let the water in the pipe be put in motion with a velocity of, say, 6 ft. per second ; then the stored energy in the water

where W=the weight of the water which in this case is 1000 lbs.

1000 X 36 The stored energy is then = 560 ft. lbs. about. So that before 64 the water could be brought to rest, 560 foot lbs. of energy would have to be expended. Now let the top

of the delivery pipe be 10 ft. above the source of supply, then

5 '6 gallons flowing over the top of the pipe would represent 560

foot lbs. This is more than would actually flow over, because of the friction of the pipe, and the work done in moving the water entering

the suction pipe, but the illustra-

tion suffices to show the reason for what has been observed in excep- tional cases. It must be explained that the work done by the pump

is represented by the water actu- ally delivered, notwithstanding the action just described, because the work done in imparting

velocity to the water is part of the total work in all cases, but with ordinary reciprocating pumps, it forms but a small part of the total power expended on the water.

Fig, 22. —Bucket and Plunger Pumps- -worked Fig. ,»22 shows a form of from Beam Engine. bucket and plunger pump used with beam engines at the New Eiver Water Works. Piston and Plunger Pump (fig. 23). —This is a pump of the character of the bucket and plunger, the bucket having been replaced by a piston. There are two valves only, as in the plunger pump. The internal

packing of the piston is an objection, but sometimes the piston is replaced by a plunger and packing boxes introduced, as in the double-acting plunger pump (figs. 25 and 26). Double-acting Piston Box Pump (fig. 24).—This is a form of pump much used for low hfts, and is generally provided with multiple valves. PUMPS AND PUMP VALVES. 55

Double-acting Plunger Pumps (figs. 25 and 26). —Both forms are much used, especially in mining work.

Three-throw Plunger Pumps (fig. 27) and Three-throw Bucket Pumps

^1 m.

Fig. 23. —Piston and Plunger Pump. Fig. 24. —Double-acting Piston Pump.

(fig. 28). —The general construction is indicated in the figures. The buckets or plungers are driven from a crank shaft with cranks placed 120° apart. These pumps are also driven direct from the piston rods

Fig. 25. —Double-acting Plunger Pump. Fig. 26. —Double-acting Plunger Pump.

of triple-expansion engines. The general idea in favour of three-throw

pumps is that of a nearly uniform flow of water. It is, however, advisable to use an air vessel of about the same capacity as would be used with

D B mil ilini

im

12 Fig. 29. — Three - throw 28. Bucket without Fig. 27 . —Three-throw Plunger Fig. —Three-throw Pump Pump. Bucket Pump. foot valves. ordinary double-acting pumps, because one of the three pumps may by accident for a few strokes, or for a longer time, become idle, and then the flow becomes very irregular, as will be seen from the pump displace-

ment diagrams (fig. 58, page 73). Three-throw Bucket Pump without foot valves (fig 29). —In this pump 56 PUMPING MACHINERY.

the water enters at A and is discharged at B, passing in an unbroken stream through the buckets, as indicated by the arrows. The displacement

of this pump is peculiar, as each bucket is displacing water in a forward direction for one-third of a revolution, so that there are three deliveries in immediate succession in one revolution of the crank shaft, and the total

displacement is the capacity of one of the barrels multiplied by 2 '6. Pumps and Pump Valves. —The practical difficulties in the working of r pumps are chiefly connected with keeping working parts watertight, and securing efficient working of the valves. Plungers are easier kept in order than any form of piston or bucket, but piston and bucket pumps are

cheaper, more compact, and occupy much less space ; they are advantage- ^~. ously used for low lifts. Almost the earliest form of valve in practical use was the flap valve,

similar to that shown in connection with Cornish pit work (fig. 131, Chap.

VII.), which is the valve now fre- quently adopted in sinking pumps

where the water is charged with grit and other substances. The valve consists of a sheet of thick leather

cut to form the valve : one part of

the leather is fastened down to the seat to form tlie hinge, and the back and front of that portion of the

leather which rises and falls is forti-

fied by means of wrought-iron plates, generally secured by means of copper rivets, which are easily cut out when

new leather is required. This valve

Fig. 30. —Pump Bucket with butterfly is improved by so hinging it that valves. it can rise above the seating at the hinge.

' Sometimes the valve is hinged in the centre ; it is then called a butter-

fly valve,' because it resembles the wings of a butterfly. Flap valves are sometimes provided with an additional flap on the back,

as in fig. 30.

This valve is known as 'Teague's valve.' In this particular case it has

been applied to a double-acting sewage pump (fig. 31).

The pump barrels (fig. 31) are 30 in. in diameter, have a 3 ft. stroke, and are so constructed as to require no foot valves. One bucket makes the up whilst the other makes the down stroke, and the displacement is equal to a pair of single-acting pumps with cranks opposite to each other. The pumps make fifteen double strokes per minute. As all the sewage pumped has to pass through both buckets, the velocity through each bucket is twice as great as that through the buckets of a pair of single-acting pumps,

which is a drawback to this type of pump, but there is a practical advantage PUMPS AND PUMP VALVES. 57 in having no foot or suction valves, so that this pump may be usefully employed if the speed of the buckets is not too great. Figs. 32 and 33 are examples of this type of pump designed for deep and shallow wells, which are suitable for use with small motors. In

IT

FlQ. 31. —Double-acting Bucket Pumps without foot valves. the deep well pump (fig. 32) a cover is placed on the rod of the bottom bucket. The cover falls into a conical seating, and the weight of the water column keeps it in place. Ashley's Pump. —A peculiar kind of pump, in which the foot or suction 58 PUMPING MACHINERY. valve is combined with the bucket, has been invented by Mr Ashley ; it is shown in fig. 34. The bucket has a pipe extending downwards, forming at the bottom a hollow plunger moving in a cylinder fixed in the pump. In the pipe joining the bucket and the hollow plunger are placed small

Fig. 32. Fig. 33.

Double-acting Wall Pumps without foot valves.

valves opening into the pipe. These valves perform the function of a foot valve. During the up stroke of the bucket water is taken through the small valves into the pipe and bottom cylinder, and during the down stroke that water is displaced through the bucket into the rising main, of hence the action is that of an ordinary bucket pump. The object the bucket. arrano-ement is to enable the suction valves to be drawn with the PUMPS AND PUMP VALVES. 59

Restler's Pump. — Pumps have been made with the valve attached to the pump rod and opening below the bucket ; such a pump is illustrated

in iig. 35.

This pump is of the type already described, a double-acting bucket pump with no foot valve. The valve, as will be seen from the figure, is opened by the downward and closed by the upward motion of the pump

Fig. Z\. —Ashley's Well Pump.

rods, but as one valve is closing whilst the other is opening, there would appear to bo ' slip ' or a backward flow of the water during that time unless the buckets are loose enough in the barrels to perform the function of a free-falling valve, and fall on the fixture on the rod during the turn of the stroke. Mechanically-moved pump valves are employed in the lUedler Pump

(fig. 36). 6o PUMPING MACHINERY.

StCtiori OfSo

Fjg. 35.—Restler's Double-acting "Well Pump. PTJMPS AND PUMP VALVES. 6l

In this pump the valves are timed in opening and closing by a mechanical connection to the engine by means of an eccentric on the engine shaft, and the necessary attachments indicated in the illustration, the object being to enable the pump to be worked at a greater speed than if the valves had a free movement ; but the speed at which a pump may be worked with free falling valves is largely dependent on the proportion of valve area to the pump displacement, and on the lift of the valve. Prof.

Riedler has lately designed a quick reciprocating pump, illustrated in

MTJ.

/

Fig. 36. —Riedler's Piston and Plunger Pump with mechanically-contirolled valves.

figs. 37 and 38. In this pump the suction valve (clearly shown in the sections, figs. 39, 40, and 41) is caused to close at the end of the stroke by means of a hollow cylindrical fixture on the end of the pump plunger.

The pump is of the differential plunger variety, single-acting on the suction side.

When the pump is completing its suction or outward stroke, the ring carried by the plunger strikes the suction valve, carrying it to its seating.

Pumps with multiple valves giving a large area and small lift are 62 PUMPING MACHINERY.

mechanically con- worked at considerable speed without having the valves pause at the end of the stroke allow trolled. Non-rotative pumps having a

Sc-N5xVsi-N^>^''^^"^^^^^^^^^^^^^^^^^'

Pump -vertical section. Fig. 37.—Eiedler's Quick Reciprocating

plan, Fig. 38.—Riedler's;Quick Reciprocating Pump—

before the return stroke com- time for the valves to drop to their seats PUMPS AND PUMP VALVES. 63 mencea, and when such pumps have a long stroke, a considerable piston speed is obtained. Valves. —The flap and butterfly valves already noticed must have a

Fig. 39. —Suction Valve Seating of Riedler's Quick Reciprocating Pump.

considerable rise to give a large opening. They are only suitable for

pumping against low lifts and at very moderate speeds. Figs. 42 and 43 show various types of valves which do not need any further explanation. In the early days of the application of the Cornish engine for the water

m^^^M^^

Fig. 40. —Suction Valve Riedler Pump— Fig. 41. —Suction Valve Riedler Pump section. —section.

supply of London, West, a Cornish engineer, invented what is known as the 'double beat valve,' and soon after Husband invented his 'four beat valve '

(fig. 44). The multiple valve may be made in various forms, such as those shown

in figs. 45 and 46. All valves which rise vertically on a spindle are improved in working by the application of a spring consisting of the india-rubber rings shown in several of the illustrations. The valve has a free lift before compressing 64 PUMPING MACHINERY. the rubber. The spring forms a buffer to the valve in rising, and facilitates

' the descent. The beat ' or contact of the valve with the seat is made

Fig. 42. —Types of Pump Valves.

watertight in a variety of ways ; sometimes by fitting the surfaces of the metal watertight, and sometimes by the introduction of an elastic material either in the valve or seat. PUMPS AND PUMP VALVES. 65

^:^

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s

I

ISSJS^ 66 PUMPING MACHINERY.

Valves are made as in fig. 47, when the weight of the water on the

Fig. a. —Husband's Four Beat Valye. Fig. 46. —Suction and Delivery Valves of multiple ring type.

Fig. 47. —Double Beat Valve in which the weight of the water is taken on Fig. 46. — Half-section of Mul- metallic surfaces, whilst the valve

tiple Ring Valve. is made watertight by means of leather.

valve is sustained by metal beats, but the valve is made watertight by means of a ring of leather above the beat. PUMPS AND PUMP VALVES. 67

In figs. 48 and 49 is shown a method of putting a group of small valves on a movable seating in a circular valve box. The main

valve seating is of cast-iron, whilst the valves are of hard vulcanite on grid seatings of gun-metal.

Fig. 50 is a plan and section elevation of a plunger pump for pumping sewage. It will be seen that the valves are hanging flap valves on vertical seatings. This arrangement prevents solid matter

resting on the valve seat. The seating carrying the group of hanging valves is removed bodily on the removal of the covers shown Fig. 48. —Valve Box with Multiple Valves in the illustrations. on Movable Seating.

Fig. 49. —Multiple Valve Seating. 68 PUMPING MACHINERY.

> BO

W Sectional Elevation.

-a

I

Plan. PUMPS AND PUMP VALVES. 69

India-rubber is largely used for valves, especially those in tlie air pumps

of condensers (fig. 51), and the hat-band valve (figs. 52 and 53). These latter are illustrations of valves and buckets of well or bore-hole

pumps. In fig. 53 is shown the ' fishing ' apparatus for drawing up the foot

valve. It will be seen that the valve seating does not fit into a conical seating, such as that shown in valve seatings of many of the other valves, but seats itself and makes a watertight joint on a gutta-percha beat let

Fig. 51. —Section of Air Pump of Condenser, Fig. 52.—Bucket fitted with showing application of disc rubber valves. hat-band rubber valves. into the bottom of the seating. It is thus very readily drawn without putting much strain on the 'fishing tackle.' Speed of Pumps. —The number of strokes per minute at which pumps may be driven depends on the type of pump, and the promptness with which the valves seat themselves before the commencement of the return stroke. By means of multiple valves which give a large water-way with a small lift, quick reciprocation may be secured. Bucket pumps do not admit of the application of multiple valves, and with such pumps a high bucket speed is best secured by means of a long stroke with a pause at the end to give time for the valves to seat them- selves. 70 PUMPING MACHINERY.

Rotative engines have necessarily a shorter stroke than non-rotative ones.

Pmnp Displacement Diagrams.—It is useful to know what is the variation in displacement per unit of time in pumps of different designs

' and combinations. The Cornish engine usually performs its indoor ' or

suction stroke in one-half the time occupied by the outdoor stroke ; hence arises the desirability of giving more water- way through the suction than through the delivery valves. Sometimes two suction valves have been provided on the suction and one only on the

delivery side ; see the engine shown in fig. 225, Chap. XIII. The variations in the pause between the strokes have also to be taken

into consideration, for it is by varying the

pause that the rate of pumping is regulated. Air vessels, when required on Cornish engine pumps, should therefore be very large. Non-rotative direct-acting engines are now usually made double-acting, as also are the

pumps ; so that air vessels on such pumps are not required to be so large as with the single-acting pump.

As an air vessel is not costly it may be

made very large, especially as it is a very perfect means of regulating the flow and avoiding shocks, and more advantageous than any other method in use. Three-throw pumps have been employed with a view to avoiding having a large air vessel, but a

Fig. 53.—Foot Valve of Bucket large air vessel is important even with three-

Panip, with hat-band valves throw pumps, for it sometimes happens that showing application of one of the three pumps ceases to act because ' fisliing tackle ' for draw- a valve has failed or for some other reason, iug the valve and seating. and then the variation in displacement per unit of time becomes so great, that the shocks wouM be severe if a small air vessel only were present. When pumps are driven from rotative engines and cranks, the pump displacement per unit of time is easily determined. If we set out a curve the ordinates of which represent the displacement to a time base for a single-acting pump, then this curve will indicate the variation in dis- placement for a single pump delivery, and a combination of such curves may be made to give the variation for any combination of pumps. Fig.

54 is for a pair of double-acting pumps with cranks at right angles; fig. 55 is for two single-acting pumps with cranks at riglit angles; PUMPS AND PUMP VALVES. 7 r

fig. 56, single-acting three-throw pumps ; fig. 57, double-acting three-throw

pumps; and fig. 58, double-acting three-throw pumps with one of the

Fig. 54. —Displacement Diagram of a pair of Double-acting Pumps with cranka at right angles.

This lower diagram shows the variation in displacement per revolution. pumps idle. Air vessels require to be proportioned with due regard to the water pressure and the variation in pump displacement. It is very

Fig. 65. —Displacement Diagram of Single-acting Pumps with cranks at right angles.

This lower diagram shows the variation in displacement per revolution. usual to make the air vessel twelve to eighteen times the capacity of the pump. Where the air vessel is not readily charged with air, a large 72 PUMPING MACHINERY.

FiQ. 66. —Displacement Diagram of a Three-throw Single-acting Pump.

This lower diagram shows the variation in displacement per revolution.

Fig. 57. —Displacement Diagram of a Three-throw Double-acting Pump.

This lower diagram shows the variation in displacement per revolution. PUMPS AND PUMP VALVES. 73 capacity should be provided. There are several ways of charging air vessels. A small air valve may be provided on the piump with a screw- down adjustment for admitting air with the water, but it is uot to be generally recommended.

The device now usually adopted is the Wippermann air charger (fig. 59). This is really a pistonless air pump actuated by water pressure froin the pump.

The vessel A is attached to the pump barrel by means of the pipe B, which is kept open when the charger is at work. During the suction stroke air is drawn into the vessel A, and during

FlQ 58. —Displacement Diagram of a Three-throw Douhle-acting Pump with one pump out of action.

This lower diagram shows the variation in displacement per revolution. the delivery stroke that air is forced into the air vessel C through the small delivery pipe, small suction and delivery valves being provided in the top of the air-charging vessel. Another form of charger is that of a small air pump worked by a hydraulic engine with pressure from the pumping main. Another method for charging by hand is to have a charging vessel provided with pipes and valves attached to the air vessel, the pipes and valves being so arranged that the vessel may be first filled with air by opening it to the atmosphere; then communication with the atmosphere is shut off, and communication opened to the air vessel. The operation may be repeated as often as necessary. 74 PUMPING MACHINERY,

In large pumping stations where there are several air vessels, it is con- venient to have an air-compressor worked by steam to enable the air vessels to be fully charged before or whilst the pumping-engines are being put to work. Air vessels require to be charged continuously or very frequently, as the

water absorbs air, and there may be leakages to be compensated for.

Fig. 69. —Wippermanu's Air Oharger for air Fig. 60. vessels of pumping-engines. —Balance Valve for maintaining a constant pres- sure in pumping mains.

Fig. 60 represents a valve used to preserve a constant pressure in the main against the pumping-engine, when a uniform pressure is not secured by use of a service reservoir. * Eeferring to the figure, D is an equilibrium valve attached to the plunger A. The plunger is loaded with weights B to the pressure it is required to maintain. C is a buffer spring to limit the rise of the weight. By this means the pressure in the main at D may vary, but on the other side of the valve it is kept constant.

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' ' / CHAPTER IV.

GENERAL PRINCIPLES OF NON-KOTATIVE PUMPING-ENGINES.

Wb must now consider in detail the principles employed in the Cornish engine, because this will explain the leading characteristics in non-rotative pumping-engines generally.

Each stroke of the engine, it will be observed, is a distinct and separate operation ; the engine starts from a state of rest and returns to it. The pump rod is put in motion and comes to rest. The pump rod is of sufficient weight to overcome the resistance of the pump, so that the steam has only to lift the pump rod, and thereby to store in it sufficient energy for doing the work on the return stroke. We have already pointed out in the history of the Cornish engine that the introduction of the plunger pump so altered

the condition under which the Cornish engine worked that it at once became possible to work the engine with a far greater degree of expansion

than had been possible as long as it remained in the stage Watt left it, which was only suited for working bucket pumps. With the bucket pump the water was lifted on the steam stroke; with the plunger pump the pump rod was lifted. There was, therefore, with the plunger pump a greater mass to be put in motion, which might have imparted to it a much higher velocity than would be safe for the bucket of a bucket pump. W V^ The energy of motion is expressed by the formula — ' in which 2 g W is the weight of the rod and its attachments, V the velocity it attains in feet per second, and 2 g=64-4. For the sake of brevity the formula may be thus approximately written

^ . The fact that the pump rod possessed weight, and was put in 64 motion and brought to rest each stroke, made it possible to use steam expansively on the piston. Figs. 61 and 62 represent steam indicator diagrams from Cornish

engines. The line A B is that of the average pressure throughout the stroke ; the shaded portion from A to C above the line represents the energy expended in putting the pump rods in motion, and the shaded 76 PUMPING MACHINERY. portion below the line from C to B represents the energy recovered, whilst the pump rods are decreasing in velocity and coming to rest. If there had been uo mass to put in motion, but merely a resistance to be overcome, the indicator diagram would have been a rectangle, and no expansion would have been possible. The reciprocating pump rod performs the function of a fly-wheel, storing energy whilst its motion is being accelerated, and giving out the stored energy whilst the velocity is being retarded.

The point C, then, is the point of maximum velocity V. By increasing either V or W the degree of expansion may be increased, but as in the Cornish engine W is constant, any increase in the degree of expansion em- ployed increases the value of V. As the energy varies with V^, an increase in the velocity with which the pump rods are lifted enables an increase in the degree of expansion to be employed. The action of the pump valves limits the number of strokes which the engine can make in one minute, but the stroke may be long or short. In the old Cornish engine the stroke of

ludicator diagrams from Cornish Engines.

Fig. 61.—Mining Engine. Fig. 62.—Water Works Engine. the pump was usually made less than that of the engine. In the new type, or compound engine, the stroke of the pump is made much longer than that of the engine (see fig. 83, Chap. V.). This leno-thening of the stroke increases the value of V, and therefore enables, even in a single cylinder, a greater expansion to be safely employed, but in the double cyhnder it is of still greater value. For the purpose of expansive working, the Cornish engine is usually made to traverse its steam stroke in one-half the time occupied by the water of the piston during the steam stroke is often stroke ; the maximum speed

as much as 600 ft. per minute ; for that reason the suction valves and suction one delivery valve pipes should be large ; sometimes two and are employed; this gives double the water-way on the suction side of the pump. The water stroke performed by the descent of the pump rod is made does not, however, slowly, but with increasing velocity ; the energy become very great because of the slow velocity, and the rod is brought to rest by the closinc of the equiUbrium valve. The steam above the piston is then PRINCIPLES OF NON-ROTATIVE PUMPING-ENGINES. 77

compressed into the clearance space, thus reducing the loss which would otherwise occur. By the use of a velocity indicator of special construction we have been able to take velocity diagrams from pumping-engines, showing the variation

in velocity during the stroke, the length of the pause, etc. Fig. 63 was taken from a Cornish engine, and at the same time the rise and fall of the pump valves were indicated as shown on the diagram, fig. 63.

When the Cornish engine is applied for town water supply from a

I ^ELOCtTieS » t uo c T I e s .

Fig. 63. —Velocity Diagram. reservoir, the load on the plunger is simply that required to overcome the resistance of the pump, but in mines the load is often greater, owing to the great length of pump rods, part of the weight of which is taken up by balance bobs as illustrated in the Cornish pit-work, fig. 130, Chap. VII. The value of W being thus greatly increased, the greater degree of ex- pansion can be employed ; in some cases we have known the pump rods to weigh over 200 tons, whilst the load on the piston was only 45 tons. This is the reason why the Cornish engine in the Cornish mines has been able to give a higher duty than Cornish engines generally ; this is very easily seen on inspecting the Cornish engine diagrams (figs. 61 and 62).

The left-hand diagram (fig. 61) was taken from a mining engine in 78 PUMPING MACHINERY.

which W was very much greater than the water load on the engine ; the right-hand diagram (fig. 62) was taken from a waterworks engine in ffhich W was very httle more than the water load on the piston. Although increasing the weight enables greater expansion to be employed, greater expansion means greater strains on the rods and con- nections, and it must be observed that, without increasing the weight to

an impracticable degree, the Cornish engine is not capable of using effectively the expansive force of steam of a greater pressure than about 40 lbs. per square inch. To be able to secure greater economy by using higher pressure steam with the proper degree of expansion, it becomes necessary to work with more than one cylinder. In the early days of the Cornish engine com-

Fio. 6i. —Diagram illustrating distribution of steam in a Compound Cornish Engine. pound engines were used, but no better result was secured than that obtained with single cylinder engines, for the simple reason that the boiler pressure in use was limited to about 45 lbs. per square inch. Now that boilers can safely carry pressures exceeding 1^ lbs. per square inch the Cornish engine may be compounded with great advantage. By com- pounding, steam can be used at 150 lbs. initial pressure and more expanded down to 8 or 10 lbs. terminal pressure with engines having pump rods of the usual weight ; this is clearly seen in the diagrams (figs. 64 and 65), which represent the distribution of steam in the Basset eno-ine illustrated in fig. 83, Chap. V.

Let steam be cut off at about half stroke in the small cylinder as in fig. 64. During the equilibrium stroke, the pressure is indicated along the line G, and the cushioning takes place at X; at the same time the PRINCIPLES OF NON-ROTATIVE PUMPING-ENGINES. 79

equilibrium steam pressure for the large cylinder is indicated along the line H, an the cushioning at Y, the condenser pressure being indicated at K, The work done in both cylinders may be taken to be the full area

1*10. 65. —Diagram showing combined power diagrams of a Compound Cornish Engine.

of the diagrams, minus the small losses caused by the passage of the steam during the equilibrium strokes, and between the two cylinders. For the sake of illustration the diagram may be taken to represent

Fig. 66. —Diagram showing variation of force or strain during the stroke for a Compound Cornish Engine.

the total work ; the area A, B, C, D, A that done in the small ; and the area F, A, D, E, F that done in the large cylinder. In order to refer all to the low-pressure cylinder, the ordinates of the upper figure must be divided by the ratio of the capacities of the two cylinders. In this case the capacities are 4'6 to 1.

In fig. 65 the work done in the small cylinder is represented by B, E, F, C, B, and that in the large cylinder by A, B, C, D, A.

The total effect referred to the large cylinder is A, E, F, D, A. 8o PUMPING MACHINERY,

In fig. 66 the line A B is drawn through the point of mean pressure, so that the rectangle A, B, C, D, A represents the total work done by the engine on the steam stroke and the area A, X, X, A, the work represented by the vis viva acquired by the load during the former part of the stroke and given out again during the latter part. On comparing this with the single Cornish engine diagram (fig. 61, page 76) it will be seen that the compound engine with more than three times the steam pressure, greatly increased expansion, and greater mean pressure does not require such a heavy mass or so great a velocity during the steam stroke for its efifective working. It will also be seen that the strains on the engine are reduced.

The initial strain is only 1'3 times the mean, whilst in the ordinary

Cornish engine it is twice the mean. It will also be observed that the work done by the small piston is applied to the pump end of the beam, so that less than one-half of the work of the engine comes on the beam centre.*

The variation of strain in the engine itself is not so great in this engine as it is in the ordinary Comiish engine, that is to say, the maximum strain does not so greatly exceed the mean resistance. The following table contains a comparison of the initial, terminal, and average pressures, maximum piston speeds, and proportion of weight of mass to water load in several practical examples which were tested some years ago, and to it has been added an example from the compound Cornish engine.

Type of Engine. PRINCIPLES OF NON-ROTATIVE PUMPING- ENGINES. I cylinder, L for the length from A to C, and P for the mean pressure of the top shaded portion of the diagram, then E = A x P x L, W = E64

'E64 V^W from which we can get the necessary quantities in further consideration of the subject of non-rotative pumping-engines. If we increase W in proportion to the water load on the piston, then higher pressure and greater expansion can be employed without increasing V, and by compounding we can carry the advantage immensely further (as already pointed out). This leads to the consideration of the balance

Fig. 67. —DiiFereiitial Engine with double quadrants and double system of plunger pumps. system of pump rods as compared with the Cornish. This sj'stem is illustrated by fig. 67, in which it will be seen that there are two quadrants or angle bobs for giving motion to the pump rods ; the two quadrants are coupled together in such a manner that one pump rod balances the other, one making the up while the other makes the down stroke. The weight to be put in motion is thus double that of the Cornish engine, with the same water load, whilst a double-acting engine is employed to work the pumps. With a compound or triple engine this system utilises the expansive force of very high-pressure steam. A very important practical advantage arises from the fact that one pump rod balances the other, so that at the end of the stroke and during the pause, when the engine is in equilibrium, no motion can take place till steam is admitted to the engine, whereas, with the Cornish engine, the weight of the rod is partly unsupported at 6 82 PUMPING MACHINEEY. the end of the stroke, if the water has failed to follow close to the plunger so as to completely fill the pump. In that case the plunger falls back on the water. With the double cylinder Cornish engine the unsupported

Fig. 68. —Differential Pumping- Engine —diagram taken during sinking operations with pumps " working on air.'' weight becomes less than that with a single cylinder. With the double rod system, should the water not have followed up the plunger, a shock can only occur by the rods being put in motion by the admission of steam.

10 Seconds

Fro. 69. —Velocity Diagram, South Durham Colliery —differential compound pumping- engine cylinders 45 in. and 72 in. diam. x 10 feet stroke. and it is possible by the use of the differential gear to so control the admission of steam to the engine that it is throttled during the time that the engine has no pump resistance ; by this means only sufficient steam is admitted to the engine to overcome the inertia and frictional resistance up to the point where the plunger encounters the water, thereby mini- mising the shock. This action is illustrated by an actual indicator diagram

(fig. 68), where it will be seen that the full pressure of steam does not PRINCIPLES OF NON-ROTATIVE PUMPING-ENGINES. 83 come on the piston until it has reached the point B, where the plunger meets the water ; in moving from A to B only sufficient steam has been

60.35 LB5 Mean Pressure

H.P. 83 Indicated Horse Power

FxG. 70. — Indicator Diagram. South Durham Colliery—Differential Compound Pumping-engine. Ratio of Cylinders 6 to 1. admitted to move the engine itself, and it has been found in practice that on this system it is quite possible to work heavy lifts on air without

10,2 Lbs. Mean Pressure »o.

L. P 8S Indicated Horse PbwpR ^1 1. Fro. 71. —Indicator Diagram. H.P. cylinder 22 in. diam. x 6 feet stroke. L. P. cylinder 54 in. diam. x 6 feet stroke. 104 strokes per minute. producing any serious shock. A steam piston velocity diagram from an engine of this type is given in fig. 69. Pumping-engines such as we are considering are subject to a sudden /^ d

PSW7?7T^V7TrT77?T?^J3T"in^Si^77^

FiQ. 72. —Diagram illustrating effect of inertia In water columns. 84 PUMPING MACHINERY.

loss of load either from the breakage of pumps or rods, failure of water supply to the pumps, or defective action of the valves; when any of these

a things occur, it is desirable that the D engine should be brought to rest as quickly as possible ; the continuance a. of working with a broken rod in the shaft, or anything wrong with the pumps, only incurs the risk of addi- tional breakage. Non-rotative engines are more easily brought to rest in the case of accidents than rotative engines. In the early days of the applica- tion of steam pumps to mining work underground, the author made use of the inertia of the water column to

secure increased expansion. The in- dicator diagrams (figs. 70 and 71) were taken from a compound steam pump at the South Durham Colliery. The pump was placed at the bottom

of the mine ; it forced the water to the surface tlirough a column of pipes which had no air vessel. The water in the column was thus put in motion at the beginning of the stroke, storing up energy, which energy was expended during the latter part of the stroke. The resistance to the engine by the water column was therefore greater at the beginning and less towards the end of the stroke, thus enabling a considerable degree of expansion to 2 U be secured. Q The function of inertia in a water

Z column may be illustrated by fig. 72. Let a be the steam -J engine, h a (0 > plunger pump, c the delivery pipe from u the pump. In the case of an under- ground engine the pipe c would be the water column reaching to the surface but it might be a horizontal pipe terminating at an air vessel d. PRINCIPLES OF NON-ROTATrVE PUMPING-ENGINES. 85

the resistance where the air vessel d Let e, f, g, h, e represent pump was part of the pump. Then when the air vessel d is removed to a distance and connected to the pump by the pipe c, the inertia of the water in the pipe c would cause the pump-resistance diagram to be altered in shape. The p^us resistance at the beginning and the minus resistance at the end of the stroke are represented by the shaded portions of the diagram. This function of inertia of water column is of importance in the appli- cation of non-rotative engines to well pumps, especially because it enables

Yia. 7i. —Worthington Compensating Device. Curve of Effect.

the engine-power and pump-resistance diagi-ams to be equated when the mechanical coQipensating device does not in itself do it, which is the case in the lever device hereafter described. Waterworks Engines.—Cornish and beam rotative engines have been largely used, but of late years quite new types have been adopted. Self- contained compound and triple direct-acting engines, both rotative and non-rotative, are now more in favour. To enable the non-rotative engine to work with the necessary expansion for economical results, compensating devices have been introduced, where the inertia of the moving parts are not sufficient for the purpose. 86 PUMPING MACHINERY.

The Worthington device (fig. 73) consists of two single-acting hydraulic plungers, A and B, working in oscillating cylinders, the plungers being attached to the piston rod of the engine. The required pressure is main-

^

i

Fig. 75. —Davey Compensating Device applied to well pumps. tained in the hydraulic cylinders by means of an accumulator kept charged by a small pump attached to the engine.

The effect of this arrangement is that an artificial resistance is put on the engine during the first half, and a corresponding assistance during the

Fig. 77. Fig. 76. 0.. ,E Zr— f

Figs. 76 and 77. —Diagrams illustrating function of Davey CompBnsating Device. second half of the stroke, the curve of effect being similar to that in fig. 74.

The Davey device is that of attaching the engine to the pump by means of a triangular lever in such a way that the pump resistance be- comes less as the stroke proceeds. In fig. 75 A A represent the steam cylinders of the engine, D the triangular lever, E, E, E points of attach- ment of engine and pumps, and B B the pumps. In this illustration the work is done on the up stroke of the pumps. It will be seen that the PRINCIPLES OF NON-ROTATIVE PUMPING-ENGINES. 87

pump B, which is finishing its up stroke, is acted on by a greater leverage effect than was exerted at the beginning of the stroke. In other words,

the stroke is made with a decreasing resistance. In fig. 76 let C, A, B, D, C be the pump resistance and C, E, F, G, D, C the steam diagram. The leverage device makes the pump resistance more nearly correspond with A, D, C, B, A in fig. 77, the inertia of the mass of the moving parts of the engine and pumps being sufficient to equate the two diagrams, the area E representing the inertia of the mass at the beginning and the area F that towards the end of the stroke. This engine has been applied largely to pumping from wells and bore-holes. Examples of such engines will be found in Chap. XIII., figs. 234, 241, 245, and Plate V. CHAPTER V.

THE CORNISH ENGINE : SIMPLE AND COMPOUND.

The Cornish Engine. —This engine is fully illustrated in fig. 78. It consists of a single cylinder A having a piston communicating its motion through an overhead beam B to a single pump rod C. The engine

beam B is carried in bearings on a thick wall, forming one of the walls of

the engine house. The outer end of the beam is directly over the shaft

and is connected direct to the pump rod. The cylinder is bolted down to a massive loading L of masonry, which must be made heavy enough to resist the total initial force of the steam on the piston.

' Attached to the pump rod by means of set-ofFs ' are the plungers of

the pumps, the pumps and 23ump rods, etc., being illustrated in fig. 130, Chap. VII. The rods are made heavy enough to overcome the resistance of the pumps.

The engine, which is single-acting, is emploj'ed to lift the rods, and the

rods are allowed to fall by their own weight, lifting the water. To secure

sufiicient strength it is often necessary to make the rods much heavier

than is necessary to overcome the resistance of the pumps. In such cases beams or balance bobs are attached to the rods either above or below ground, having counterweights to take up the surplus weight (see pit-

work, fig. 130, Cliap. VII.). The distribution of steam in the engine will be

understood from the section of the valves and nozzles given in fig. 79, in

which A is the steam valve, B the equilibrium valve, and C the eduction or exhaust valve. D is a pipe connecting the two ends of the cylinder,

commonly known as the ' equilibrium pipe.' The working of the engiae

is thus described. Steam is admitted above the piston through the steam

valve A (fig. 79), the equilibrium valve B remaining closed, and the exhaust valve C open. The valve A remains open during the time the piston

makes about one-third of its stroke ; it is then closed by the action of the valve gear, and the remainder of the stroke is completed partly by the decreasing pressure of the expanding steam and partly by the momentum

of tlie pump rod and attachments. At the termination of the stroke the THE COBNISH ENGINE : SIMPLE AND CX)MPOtrND. 89

eduction valve C is closed and also the injection valve shown at N in fig. 78.

The pump-rod having been raised to the full extent of its stroke is

Fig 78. —Cornish Engine, as applied to a mining shaft. partly supported by the water in the pumps under the plungers, and partly by the terminal pressure of the steam above the piston. The equilibrium valve B is then opened, and the steam above the piston is allowed to pass down tlie equilibrium pipe D to the under side of the 9° PUMPING MACHINERY. piston ; the pump-iods being free to fall by their own weight, descend, and in doing so lift the water in the pumps. The rods falling under the influence of gravity have an accelerating motion, but they are brought to rest at the completion of the stroke by the closing of the equilibrium valve

B ; that valve having been closed a little before the end of the stroke, the momentum of the moving weight is then expended in cushioning the steam confined above the piston. The piston is now brought to rest, and the

Fio. 79. —Cornish Engine. Steam nozzles and valves. next stroke is performed by the opening of tht steam valve A and the eduction or exhaust valve C. The eduction valve C is made to open a little before the steam valve, and at the same time the injection valve (N in fig. 78) of the condenser is opened. It will be seen that when steam is admitted above the piston, the steam from below is exhausted into the condenser. Keferring to fig. 78, which is a general illustration of the engine, D is the steam and equilibrium valve box, E the equilibrium pipe, F the exhaust valve box, G the exhaust pipe to the condenser, H the condenser, J the air pump, and N the injection valve. THE CORNISH ENGINE : SIMPLE AND COMPOUND. 91

The air pump and condenser are placed in a tank of water from which

the injection water is taken through the valve N. This valve is opened at the same time as the exhaust valve by the action of the valve gear. The valve gear itself is shown at M, and is fully described and illustrated in Chap. XL, figs. 177 and 178. The steam pressure on the piston at the termination of the steam stroke is not sufficient to support the weight of the pump rods. If, therefore, the water in the pump has not closely followed the plunger, the rods will be unsup- ported at the completion of the stroke. When this happens, the rods fall back, causing the plunger to strike the water, and producing a shock. On the other hand, during the steam stroke the loss of resistance arising from the breaking of a rod or other cause may result

in the piston making its stroke with undue velocity. To provide a- gainst contingencies of this kind, banging beams are provided in and over the shaft with catch-pieces on the rods to prevent eULL CORNISH E'NGINe. the piston striking the Fig. 80. cover on the outdoor stroke, and spring beams and catch-pieces are provided at the engine end of the beam to limit the indoor stroke.

The spring beams are shown at R (fig. 78), and the catch-pieces on the

engine beam at S. Devices are employed such as the differential valve gear (see Valve Gear) to cause the valves of the engine to become closed, when, owing to loss of resistance, the engine has exceeded its normal speed.

Sometimes the Cornish engine is made without an overhead beam, the cylinder being placed over the pump with the piston rod attached directly to the pump rod. Such engines are known as Bull engines.

An illustration of such an engine is given in fig. 80. Cornish Engine Details. —A section of the cylinder is given in fig. 81. In the stuffing-box between the packing is placed what is termed a lanthorn brass or bush A, consisting of a perforated and movable cylinder of brass fitting around the piston rod with the openings through the side. 92 PUMPING MACHINERY.

Opposite this lanthorn bush and in the side of the stuffing-box is fitted a small pipe connected to the main steam pipe.

The object of this arrangement is to prevent air leaking into the cylinder around the piston rod and vitiating the vacuum. With steam pressure in the middle of the packing, steam might leak into the cylinder, but air could not. This was of considerable importance in the Cornish engine, because the mean pressure on the piston was not more than 12 or

13 lbs. per square inch, and a small back pressure in the condenser caused by air leaks, represented a consider- able percentage of loss. The lan-

thorn brass is very usefully and frequently employed in the stuffing- boxes of air-pumps of modern engines, the pipe being taken to the hof^well instead of to the steam pipe, and water being used instead of steam to prevent air leaking into the air-pump. Air-pump and Condenser. — A

section of the Cornish engine air-

pump and condenser is given in

fig. 82. The air-pump A, and bucket B, are shown in section. The bucket is provided with a valve D, usually of india-rubber working on a brass grid C. A head valve or swimming

cover F is placed in the hot-well closing on a wooden beat let into the top of the air-pump. The bucket rod E passes through a stuffing-box. G is the condenser, H the exhaust pipe, and J the inlet for injection Cornish Engine Steam Cylinder. water.

Valve Gear. —The Cornish form of valve gear, and the application of the differential gear to the Cornish engine, are fully described in Chap. X. •

Duty of Cornish Engines.—In Chap. I. we have noticed the progress of economy efl'eoted in the Cornish engine. The maximum economy was obtained by using the greatest boiler pressure and the highest rate of expansion which the principle of the engine would permit, the limits being about 40 lbs. boiler pressure and 4 to 5 expansions. The average duty was about 50 millions on 112 lbs. of coal, or in the best examples from 60 to 70 millions. In some cases 90 millions have been obtained on 112 lbs. of coal with a high evaporation, and results as high as 130 millions have been claimed on 94 lbs. of coal, but such a high result is impossible. THE CORNISH ENGINE : SIMPLE AND COMPOUND. 93

One H.P. per hour is equal to 1,980,000 foot lbs., or, say, in round numbers, 2 millions.

130 millions duty = — =65 H.P. hours.

94 —- =1'45 Ihs. of coal per P.H.P. per hour. 65 With an evaporation of 10 lbs. of water per lb. of coal, the feed water

Fig. 82. —Cornish Engine Air-pump and Condenser. per pump H. 1'. per hour would then be 14"2, and assuming a mechanical efficieucy of 80 per cent., we have 11 '36 as the consumption of steam per 94 PUMPING MACHINERY.

I.H.P. per hour. Taking the initial pressure as 40 lbs., we have as the 10'7 efficiency ratio —— = 90 %. The best efficiency ratio obtained with

Cornish engines is about 60 % to 65 %. Expressed in weight of steam, the average engines used from 26 to 30 lbs. of steam per I.H.P. per hour. A better result has been obtained on short trials, and a consumption as low as 18 to 20 lbs. per I.H.P. per hour has been recorded, but no further economy could be obtained with a single cylinder, nor could better results be secured by compound engines with the same boiler pressure. It is only quite recently that high steam pressure has been applied to the Cornish engine.

The single cylinder Cornish engine is limited to 4 expansions, and even then the velocity of the piston during the indoor stroke is very great (see (ig. 63, Chap. IV.).

Four expansions with 40 lbs. initial steam pressure gives 10 lbs. as the terminal pressure.

The only method of increasing the initial pressure and the ratio of expansion is by the use of a second cylinder. By the use of a second cylinder the strains on the engine and pump rods are reduced, and a greater range of expansion is secured, thus adapt- ing the engine to the use of high-pressure steam. The author having recently to design a pumping-engine for the Basset Mines, Cornwall, adopted the Cornish system of steam distribution. By employing two cylinders he succeeded in using steam of 150 lbs. boiler pressure.

Fig. 83 represents an elevation of the engine. A is the high and B the low pressure cylinder, both cylinders having tlie Cornish cycle of steam distribution. The pistons of both cylinders are connected to a steel rock- ing beam C, one piston making the up whilst the other makes the down stroke.

The beam extends beyond the small cylinder over the shaft, and gives motion to the pump rod. The inner end of the beam is made of box section to receive balance weights. The cylinders are 40 and 80 in. in diameter, and have 9 and 10 ft. strokes respectively. The stroke of the pumps is 13 ft. ; the pump plungers are 18 in. in diameter, and the present pit-work extends to a total depth of lOOi ft. At 8 strokes per minute the actual H.P. is 360. No trials have yet been made as to the consumption of steam, but the consumption of coal has been found from week to week to be one-half that consumed by a good Cornish engine on the same mine doing similar work. Practically the duty is over 90 millions on the coal used. The evaporation is probably 8 lbs. of water per lb. of coal. The duty then on an evaporation of 10 lbs. of water per lb. of coal would be 110 millions.

It is not likely that this engine will give as high an efficiency ratio as 60 per cent., but an efficiency ratio of 50 per cent, with 150 lbs. steam THE CORNISH ENGINE : SIMPLE AND COMPOUND. 95 would make the feed water per I.H.P. per hour equal to 16 lbs. An eflBciency ratio of 60 per cent, would reduce the feed water to 13-3 lbs. In this engine a disused cylinder and nozzles of an old Cornish engine were used as the low pressure cylinder. An entirely new engine may be expected to give a much better result. The water load on the engine (all referred to the large cylinder) is

Fig. 83. —Davey's Compound Cornish Engine, Basset Mines.

of stroke, 9 ft. L.P. cylinder, 80 in. diameter H.P. cylinder, 40 in. diameter ; length ;

length of stroke, 10 ft. Pumps, 18 in. diameter ; length of stroke, 13 ft. Total height of lift 1000 ft.

equal to 30 lbs. per square inch. This is double the proper load of the old Cornish engine. An 80-inch engine in this system may be made double the power of the ordinary Cornish engine, and as the first cost of the engine is not greatly in excess of that of the single cylinder engine, the cost of the new engine per H.P. is lower. 96 PUMPING MACHINERY.

It will be seen that by placing the cylinder A on the pump side of the beam centre instead of by the side of the cylinder B, the strain on the beam and the weight on the centre are greatly reduced. The cylinders may, however, be brought together by adopting a modification of the parallel motion beams, designed by the author for the differential engines illustrated in fig. 100, Chap. VI., and fig. 233, Chap. XIII. The modification necessary is shown in fig. 84. The main beam Q is actuated throiigh tlie secondary beams forming a parallel motion for the piston rods. The outer ends of the secondary beams are anchored to the foundation by means of links. One end of the

Fig. 84.

Fig. 85.

Figs. 84 and 85. —Conipouiid Cornish Engine, with parallel motion beams.

represents the cut-off motion for the The lower fignre steam valves ; a description of a form of tliis motion is also given in Chap. XL, on valve gears. main beam would be over the shaft, and the other end made to carry a balance weight. Fig. 8.5 represents the gear for giving motion to the steam valves. C is a rocking shaft actuated by means of the differential gear, and D a rocking shaft partaking of the motion of the engine beam. A A are valve rods to the admission valves to the engine cylinders receiving motion from the bell-crank levers E E by connections to G G and F F. The motion of the shaft C operates to open the valves, whilst the ;

THE CORNISH ENGINE : SIMPLE AND COMPOUND. 97

motion of D closes them. By suitable adjustments the out-ofF may be made to take place at any point of the stroke. The Basset engine has a surface condenser with 900 square feet of tube surface.

It is also provided with the author's compound system of heating the

feed water, by mieans of which the water is heated to a much higher temperature than can be obtained from the exhaust steam. That the construction of the engine may be understood, we have pro-

FiG. 86. —Section of Compound Cornish Engine—Waihi Mine. duced in fig. 86 a section of an engine on the same principle, designed by the author for the Waihi Mines.

In this example the valves, cylinders, and feed heater are all in a line, so that one section shows them all. Steam from the boiler is admitted through the valve c under the small piston ; at the same time the steam above that piston is admitted to the large cylinder through the valve e the steam below the large piston passes to the condenser through the exhaust valve g and the feed-water heater h. At the completion of the 7 98 PUMPING MACHINERY. steam stroke the valves c, e, and g close, and the equilibrium valves d and / are opened. The steam below the small piston then passes to the other side, and the steam above the large piston passes into the space below it.

Both pistons now being in equilibrium, the pump rods fall by their own weight, lifting the water in the pumps. Towards the completion of this stroke the equilibrium valves d and / are closed, and the steam above the large and below the small piston being cushioned, the pump rods arc thereby brought to rest. The feed- water heater is divided into two sections, j and h: the cold feed-water enters at n and passes around the tubes in h ; then it passes in a pipe from the top of h to the bottom of the heater j, in which it passes around the tubes and then through the pipe m to the boilers. In h the water takes up heat from the exhaust steam from the large cylinder, whilst in j it is further heated by steam taken from the equilibrium stroke of the large cylinder. It will be seen that the steam passing the equilibrium valve / has done its work, and is only retained below the piston to keep the cylinder hot and to be discharged into the condenser during the next stroke.

In the pipe to the second section of the heater j is a non-return valve k, so that steam may pass to j, but cannot return. In this way the steam pressure in the heater ^ is practically maintained at the pressure of the equilibrium steam. The effect of this arrangement

is that the water in the heater h is subject to a temperature of 100° Fahr., whilst in j the temperature depends on the temperature of the steam at the end of the stroke of the large piston. In the case of the Basset engine that temperature is 190°. The steam condensed in the heaters passes through a small pipe at the bottom to the exhaust pipe. Practically all the heat thus put into the feed-water is taken from the waste heat of the engine. The steam valves of the engine are actuated by the differential gear. Duty Reports. —The economy of an engine, as ascertained by an accurate test of twelve or twenty-four hours' duration, enables us to compare its per- formance with that of another engine tested under similar conditions, but the actual consumption of steam or coal per unit of time as deduced from the consumption during long periods is much greater than that ascertained by a scientific trial. In such a trial it is alwayf necessary to preserve a uniformity of conditions throughout. In actual work the general results are influenced by change of speed, stoppages, and irregularities of all sorts, but for an engine trial to have a scientific value, the irregularities of ' ordinary working must be excluded. In our history of the pumping-engine we have already noticed the system of duty reporting instituted in Cornwall in the year 1811. At that time Welsh steam coal was exclusively used in the Cornish mines, so that the evaporative efficiency of the coal may be assumed to be fairly uniform. The type of boiler in use was the single flue or Cornish boiler, THE CORNISH ENGINE : SIMPLE AND COMPOUND. 99 invented by Trevithiok. The setting of the boiler was always the same, the gases passing from the fire along the flue tube, then back through the side flues, and finally through the bottom flue to the chimney. The engines were fixed with the bottom of the cylinder a few feet above the top of the boiler, and as near the boiler as possible to minimise the loss of radiation from the steam pipe. The steam supply pipe to the jacket was large, and the drain pipe, from 3 to 4 in. in diameter, went direct to the boiler. Cylinder nozzles and steam pipes were well clothed, and the engines were worked continuously at practically a uniform speed. The working conditions were therefore fairly uniform, and that being so, the duty expressed in millions of foot lbs. per cwt. of coal had a commercial value. The duty reports, although defective in construction, served a good purpose by stimulating an ambition for each engineer to do his best to secure economy. From a scientific point of view the construction of the duty reports was bad and inaccurate. The following is a copy of the duty report as at first constructed, and even now used notwithstanding the fact that the working conditions are much more varied than they were when the reports were first instituted. It is from Lean's Engine Reporter and Advertiser, February 1899 :— lOO PUMPING MACHINERY.

•-I .2 S r\ THE CORNISH ENGINE : SIMPLE AND COMPOUND. lOI

The most important items which vitiate the reports are— 1st, the coal

used is now of very varying quality ; 2nd, the boilers have varying

efficiencies ; 3rd, where the pumps viork on the incline the load is assumed to be that of a vertical shaft with a depth equal to the length of the

incline ; 4th, the actual length of stroke is more or less uncertain ; 5th,

the coal used is taken from the invoices of the coal delivered, a deduction for the coal in stock being usually guessed at from an inspection of the

heap. These are defects which have been always more or less present in the system. These reports enable us to form a general idea only, of the results, but the actual performances of Cornish engines can be determined from the tests now made on engines and boilers separately.

The following table shows the values of foot lbs. of duty per 112 lbs. of

coal expressed in lbs. of coal per pump H.P. per hour and in lbs. of steam per I.H.P. per hour, with different rates of evaporation. CHAPTEE VI.

TYPES OF MINING ENGINES.

Various Types of Pumping-Engines.—The requirements and condi- tions of mining are so varied that quite different types of engines are required.

Since its introduction the steam pump has been largely employed underground in forcing water to the surface. In a few cases in collieries the boilers also have been placed underground, quite near the engines, but the general practice has been to transmit the steam from the surface.

Fly-wheel engines are also used underground ; they are usually of the cross compound type, with double-acting plunger pumps. Underground pumps are also worked by means of hydraulic power transmitted from the surface. This method of pumping is dealt with in a separate chapter. Electricity also is coming into use as a medium of transmission of power to underground pumps, but up to the present time it has not been largely used except for small powers. The chief difficulty has been in the application of the quick-running motor to the slow-running pump, involving high-speed gearing, belts or ropes, all of which are practically objectionable. Attempts are now being made to produce a quick-running pump and a slow-running motor, thus minimising the gearing required between the motor and pump. It is in this direction that improvements must be made if electricity is to be applied to heavy pumping. See chapter on Hydraulic and Electric Pumping. The main objection to having the pumping plant underground arises from the circumstance that as surface plant must be erected when sinking

the shaft it is usually found convenient to adapt it for the permanent as well as for the temporary work. Large pump rods take up room in the shaft, but it is a question whether any of the forms of underground steam engines or systems of power transmission are so economical in fuel and upkeep as a well-desigued

TYPES OF MINING ENGINES. 103 surface engine and pit-work wlien the power applied is considerable. Surface engines, both non-rotative and rotative, vary very much in design and arrangement.

The old Cornish engine and its pit-work has been superseded by improved forms ; but long experience with the Cornish engine has demon- strated the value of working with engines which have a distinct pause after each stroke. Many Cornish engines have worked for half a century with very little cost for maintenance. Rotative engines are used to actuate heavy pit-work, but when so applied, there is more vibration, more wear and tear involving greater cost of upkeep than there is with non-rotative engines. Non-rotative engines usually have the same speed of stroke, whatever number of strokes they may make per minute, the variation in the number

Fig. 87.— Regnier's Pumping Eiigiae, in whioli an auxiliary engine is employed to help the engine over the deadpoint when moving slowly.

of strokes being governed by the pause between the strokes, but with rotative engines there is a difficulty in running very slowly, and a pump

which is being moved very slowly is very frequently inefficient. In such cases a leakage of air, or a leakage of water past the pump valves, gives rise to shocks and to a loss of effect. In other chapters we have illustrated and described different forms of non-rotative engines. We will now briefly notice some of the types of both rotative and non-rotative engines in use. When direct-acting rotative engines are employed, very heavy fly-wheels centre at slow speeds become necessary to insure getting over the ; attempts have been made to work the engine slowly with a light fly-wheel by the employment of a small auxiliary engine having a crank at right angles to the main crank to assist the engine over the deadpoint, but the system has 104 PUMPING MACHINERY.

not found favour in this country, nor does it appear to be a good practicable method of getting over the difficulty. At the end of the stroke of the main crank, when the auxiliary engine comes into full operation, there is no resistance except the frictional resistance of the engine, and the auxiliary engine naturally produces a quick speed just at the time when the actual pause is desirable for the proper action of the pump valves. Several engines have been built on this plan, such as Regnier's engine (fig- 87).

Kley's Pumping-Engine. —Kley .has also endeavoured to overcome the

difficulty of the deadpoint by his engine illustrated in fig. 88. In this engine the object has been to combine the advantages of the

Fig. 88. —Kley's Engine, in wliioli the fly-wheel does not turn completely round when goiug slowly, but turns backward and forward, the piston not making a full stroke. When running fast the engiue works as an ordinary rotative engine. non-rotative with those of the rotative engine, and%to obtain a pause at the end of the stroke with an engine having a crank connecting-rod and fly-wheel. Should the speed of the engine be too great for the pause, then the engine would go ou working like an ordinary rotative engine. To secure this double effect a peculiar construction of valve gear was necessary. The engine valves are of the ordinary double-beat type, and are operated by a gear which is a modification of the Cornish gear, having tappets and catches so arranged that the valves are operated whether the crank should happen to go over the centre or not. Should the crank get over the centre, it continues to work in that way ; if not, then the piston makes a TYPES OP MINING ENGINES. IO5

shorter stroke, and the engine works as a non-rotative engine. At high

speeds the fly-wheel goes continually round : at slow speeds it moves back- wards and forwards without turning the centre.

An engine of this kind has been erected at Idria : it was built by E. Skoda of Pilsen, and has been provided for the extension of workings 255 metres below the adit level, as a substitute pending the reconstruction of

two existing pumping plants driven by water wheels. It is based on the system of combining a double-acting rotatory engine with a cataract so

that it may be worked either continuously or intermittently through a range of speed between half a revolution and eighteen revolutions per minute. The arms of the main beam placed below the cylinders are of unequal length, giving a stroke of 1'5 metres in the shaft and 2 metres on the low-

pressure piston, with a further length on the steam side to a total of 6|- metres which carries the balance weight of the pit- work and the connect-

ing rod for the fly-wheel, giving a radius of 1 "8 metres for the crank path.

The pit-work is of the Rittinger telescopic form, with differential plungers,

the total lift of 259 metres being divided over three setts of 55 '6 metres,

100 metres and 105 '5 metres rise respectively. The main rods, made of Siemens-Martin steel of 32 tons tensile strength with 20 per cent, elonga- tion and 45 per cent, contraction at fracture, are circular in section and tapered in four thicknesses of 135 millimetres, 110 millimetres, 80 milli- metres and 75 millimetres. The total weight of the pumps and pit-work

is 65'17 tons, of which 50'5 tons are in the moving parts, and the water

load is 27'616 tons on the up and 14'02 tons on the down stroke. The maximum working stresses on the rods correspond to a 10 fold safety factor at the top, 10-3 fold in the middle, and 13-8 fold in the

bottom sett. The load on the up stroke is 27-6 -1-50-512 = 78-112 tons against 50-512 - 14-017 = 36-495 tons excess power on the down stroke. The

latter quantity is nearly all counterbalanced by cast-iron weights amount- ing to 20-4 tons attached to the inner arm of the beam between the points of attachment of the piston and connecting rod. A portion of the weight

is also provided by the steam pistons, which are unusually thick and heavy, that of the high-pressure cylinder weighing 26 owts. and that of the low- pressure cylinder 66-6 cwts. The fly-wheel, 7-5 metres in diameter, weighs 20-65 tons, and the total weight of the engine and condenser is 137-2 tons. The average working speed on the trials was eight to nine revolutions per minute, corresponding to between 120 I.H.P. and 150 I.H.P., while the steam consumption under the most favourable conditions is 9-74 kilogrammes per H.P. hour. Wood and coal of a low (six-fold) evaporative power are

used as fuel. The normal work of the engine is lifting 1^ tons of water per minute to a height of 270 metres when making six revolutions pei minute, corresponding to 100 gross and 75 efl'ecti-s-e H.P. which can be doubled when required. The results of three years' working give the steam consumption as 13-G6 —

io6 PUMPING MACHINERY.

kilogrammes per effective H.P., that of aa underground compound con- densing engine of 120 H.P. in another shaft being 14-39 kilogrammes. The total cost of the engine, boiler, pit-work and buildings was £9363, of which amount £3912 are charged to the engine and the travelling-crane in the engine-house, and £2809 to the pumps and pit-work.* There are other forms of rotative engines for actuating the single rod system of pumps. Two of these are shown in figs. 89 and 90. Geared engines have been used both for the single and double rod

Fig. 89. —American Compound Rotative Pumping-Engine for actuating a single line of pump rods.

system of pumps, but such engines cannot be said to be suitable for heavy pumping. An example of an American geared engine is given in fig. 91, and the description of another is as follows : • The pumping machineiy used in the iron and copper districts of Michigan usually consists of Cornish plunger pumps which are operated by geared engines, the latter making from three to sixteen strokes for each stroke of the pump. The largest plant of this type yet erected is that of the Calumet and Hecla copper mine at Calumet, Mich. There are two lines of pumps vary- ing in diameter from 7 in. to 14 in., and with an adjustable stroke varying

from 3 ft. to 9 ft. The object of the adjustable stroke is to diminish the

* Mill. Froc. Inst. Civil Engineers, cxxxvii. TYPES OF MINING ENGINES. 107

capacity of the pumps in the dry season. Each hne of pumps is driven from a crank placed on a steel spur-wheel shaft 15 in. in diameter, making ten revolutions per minute. The mortise spur wheels have a diameter of

Fig. 90. — .\m'>.rioan Compound Ritative Eagine for actuating a single line of pump rods.

221 ft. at the pitch line, with two rows of teeth, each 15 in. face. The

pitch is 4:-72 in. Engaging with the mortise wheels are pinions of gun iron of 4 ft. 6 in. diameter, placed on steel shafts of 12 in. diameter, and making

american geared pumping engine.

Fig. 91.

fifty revolutions per minute. The r2-in. pinion shafts are driven through

mortise wheels 12 ft. in diameter and 24 in. face by pinions, 3 ft. 9 in. in diameter, which make 160 revolutions per minute. The engine is 4700 [o8 PUMPING MACHINERY.

H.P., and in addition to driving the pumping machinery does the hoisting and air-compressing for the Calumet mine. In the same building with the mine pump gearing is a duplicate arrangement for operating the man engines. In order to operate the mine pumps and man engine for the Hecla mine, it was necessary to use rocking shafts, which are made of gun- iron and hollow ; they are 32 in. in diameter outside, and the thickness of metal is 4|^ in. The pump rocking shaft is 39 ft. 4|- in. long over all, in two sections, and weighs 40 tons. Rockers are placed on each end of this shaft ; one is connected with a crank on the mortise wheel shaft, and the other with the surface rods that work the pump bobs. These rods are of

Norway pine, 12 in. by 12 in. in section and 1000 ft. long. There are two bobs, one above the other, with axes at right angles, each weighing about 25 tons. The connection from the upper bob to the lower has hemispherical pins and brasses to accommodate vibrations in right-angled planes. The slope of the main pump is 39°, and the machinery has been designed to

Fig. 92. —Geared Pumping-Engine, having weights hanging on cranks on an inter- mediate shaft, so arranged as to equalise the resistance on the engine.

raise water from a depth of 4000 ft. The pumps are of the usual Cornish plunger type with flap valves. There is an auxiliary engine of the Porter- Allen type for driving the pumps and man engines when the main engine is not working. It makes 160 revolutions per minute, the same as the rope wheels. The seeming complication of this arrangemtnt is due to the fact that it had to be adapted to existing works for increased depths, and to be put in without interfering with the daily operation of the mine.

One of tlie objectionable features in all geared engines is, that at the time of the turn of the stroke, when the pump offers no resistance, the speed of the engine becomes greatest ; the engine runs with a variable load of such a nature that the pumps turn the stroke quickly when a pause would be desirable. This acceleration of speed at the end of a stroke is a defect, to correct which Mr Charles Bridges in America, in 1883, patented a device shown in fig. 92. The intention was to equalise the resistance on the TYPES OF MINING ENGINES. 109 engine by means of balance weights, but the device does not appear to have been put in practice. Non-rotative pumping engines in mines, when worked on the multiple

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cylinder system, have generally the Woolf system of steam distribution. The receiver system demands a greater energy of mass to enable the ex- pansion of steam to be complete, and, therefore, the strains imposed on the I lO PUMPING MACHIlSrERY. moving parts become very great. It is not expedient to employ the receiver system in either non-rotative or direct-acting rotative engines employed to actuate heavy pit-work. Mines are sometimes drained by means of steam engines placed at the bottom of the pit. When rotative engines are so employed, it is practicable to use the receiver system, provided the fly- wheel is heavy enough. The high- and low-pressure pistons should actuate double-acting pumps direct, and be coupled to the crank shaft with cranks at right angles. When non-rotative engines are employed, the inertia of the water column may be made use of, as explained on page 84, and the most economical result with such engines is obtained with long stroke tandem compound or triple engines. Duplex and other short stroke steam pumps lose much by clearance. 1 in. clearance in a 15 in. stroke is nearly 17 per cent., whilst on a 5 ft. stroke it would only be one-fourth of that amount. Pumping-engines when employed for the water supply of towns, etc., are not subject to the same practical considerations as mining engines, because they are generally applied under different conditions and in quite a different way. Compound Cornish Engine.—In figs. 93 and 94 we give the elevation and plan of an engine designed by the author for the Waihi Mines, New Zealand. Both cylinders have the Cornish cycle of steam dis- tribution. A section of the cylinders showing steam-valve nozzles and feed-heaters is given in fig. 86 and fully described in Chap. V., page 97. The cylinders are 45 in. and 90 in. in diameter, both having a stroke of 8 ft. The pumps are of the plunger type, 19 in. in diameter, and have a stroke of 10 ft. The total lift is 1000 ft.

The pumps are shown in figs. 132 and 133, Chap. VII. Fig. 93 is an elevation and fig. 94 a plan of the engine. The condenser is of the surface type, and is placed with the air-pump in a water tank outside the engine- house, as shown in fig. 94. The boiler pressure is 120 lbs. Pumping Shafts. —Where the shaft is entirely used for the pumping plant, the steam cylinders may be placed directly over the pump rods, as in figs. 95 and 96, and then the balanced system of pump rods may be em- ployed, the engine being a compound double-acting engine with valve nozzles, as shown in figs. 97 and 98. Another practical example of such an engine is given in fig. 99. • This form of engine has been frequently applied in German collieries by Mr Wippermann, who has also designed and erected the engine illustrated in fig. 100. In this engine the parallel motion beams take the place of the triangular rocking levers of fig. 99. In the collieries of this country the horizontal engine (fig. 67,

Chap. IV.) is generally preferred, because it gives more room at the top of the shaft.

In fig. 101 we illustrate a pumpingengine at the Calumet and Hecla TYPES OP MINING ENGINES. I I I 112 PUMPING MAOHINERY.

Fio. 95.

Fig. 96.

Figs. 95 and 96. —Elevation and Plan of a Pair of Compound Engines placed diectly over the shaft, each engine actuating a double line of rods. TYPES OF MINING ENGINES. 113

Mine for pumping water for use in the stamp mills. There are three pumping-engines, two of which have a capacity of 20,000,000 gallons per

day, while that of the third is 10,000,000 gallons per day.

The water is elevated between 50 and 60 ft., and is used for treating the stamped rock. Two of the engines are of the inverted compound beam

and fly-wheel type (fig. 101).

The largest of the compound engines is named ' Ontario,' and has a vertical low-pressure cylinder 36 in. in diameter, and a high-pressure cylin-

der 17|^ in. in diameter, the stroke of both being 5 ft. These are inverted

Figs. 97 and 98. —Valve Gear and Section of Nozzles and Valves of Compound Double- acting Engine with Cylinders over Pump Rods.

Elevation and plan of two engines oyer one shaft are given in figs. 95 and 96.

over a beam or rocker, and the pistons are connected to opposite ends of the same (fig. 101).

The beam attachment of the main connecting rod is made to a pin placed above and midway between the pins for piston connections. The throw of the crank is 5 ft. There are two differential plunger pumps having upper plungers 20 in. in diameter, and lower plungers 33 in. in diameter, with a stroke of 5 ft. These pumps are vertical, and placed beneath the engine bed-plate, to which they are attached by strong brackets. The pump under the low-pressure cylinder is worked direct from its crosshead by an extension of the piston rod. The other pump is worked by a trunk connection from the opposite end of the beam. The radius of the beam is but 50 in., but the connections to it are made very long by links. 114 PUMPING MACHINERY,

The lower plungers work through sleeves in diaphragms situated in the centre of the pumps.

— Engine with cylinders directly over the Fig. 99. "Vertical Compound . Double-acting shaft, the engine actuating a double line of rods—used in some German collieries.

In these diaphragms the openings for the delivery valves are made. These valves are of brass, faced with rubber, and closed with brass spiral TYPES OP MINING ENGINES. "5 springs. Their diameter, however, is 5J in., and there are 72 suction and 72 delivery valves for each pump. It will readily be seen that the action

Fig. 100. —Double-acting Compound DifiFerential Engine.

of these pumps is similar to that of the bucket and plunger, each pump having one suction and two deliveries for each revolution of the engine. ii6 PUMPING MACHINERY.

' The Ontario ' is designed to run at a maximum speed of 33 revolutions per minute.

In fig. 102 we give an illustration of Barclay's grasshopper beam engine. This engine has been made both with single and with compound cylinders. The engine may be single or double acting.

Fig. 101. —Pumping- Engiue— Calumet and Hecla Miue.

When of the latter construction, a heavy balance beam is required.

The valve gear employed is of the ordinary Cornish type. Fig. 103 represents a small compound Cornish engine supported on a steel framing. This engine was designed to be independent of masonry foundation, in order that it might be easily taken down and re-erected at another place TYPES OF MINING ENGINES. 117

with little expense. In fact, it is semi-portable. The connection of the piston rods with the beam is made by means of a triangular connecting rod. The steel framing which carries the engine also forms a support for

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Fig. 102. — Barclay's Grasshopper Beam Eiigine. screw gear for the purpose of lowering and lifting the sinking lift in the shaft. The steam valves are of the ordinary D-slide valve form, actuated by means of the differential gear. ii8 PUMPING MACHINERY.

Example of large Pumping-plant.—The pumping-plant illustrated in the folding plate (Plate VII. ) and the following engravings is probably the largest pumping-plant erected on one shaft. It was designed by the author for the Miike mine in Japan. The complete pumping-plant is capable of raising 9000 gallons per minute from a depth of 900 feet when the engines are running at six strokes per minute. This equals 58,000 tons of water

Fio. 103.—Small Compound Cornish Engine with triangular connecting rod attach- ment to beam showing suspending rods and screws for bucket lifts.

in twenty-four hours, or 13 miUion gallons. The total horse-power in

water lifted is 2500.

The shaft is rectangular, 41 ft. long by 12 *t. wide, and is made to accommodate four sets of twin pit-work and two pairs of winding cages. Plate VII. shows the general arrangement of the surface plant — the pit-head frame, the pumping-engines, winding-engines, and steam capstans. A perspective view of the pit-head- frame is given in fig. 104. The following illustrations give details of the pump work, the methods em- ployed in sinking the shaft, the arrangements for sinking, permanent

pumps, etc. PLATE VII.]

PUMPING ENGINES WINDING ENGINI CAPST.

Japan. General Arrangement of Pumping and Winding Engines. —Shaft 41 ft long x 12 ft. wide.—Muke Mines,

TYPES OF MINING ENGINES. 119

riimjnng-Engiup?. —Tlicre are four puniping-eiigiiies which are arranged side by side in one large house. The surface condensers of the engines

are [ihiced in tanks outside tlie engine house.

Tlie engines and condensers arc clearly shown in ]ilan and elevation on

the folding plate, whilst the engines themselves are given in detail in figs. to on 105 107 ; page 120, fig. 107 sliows a section of the steam cylindei-s,

and figs. lOo and lOfJ the valve gear, etc. The valve gear is of the dif-

ferential tyjic actuating drop valves. 'i'he cylinders are 45 and 90 in.

in diameter and have n 12-ft. stroke. A section of tlie air pump is given

Fic. 101. — ^terl Fit head Fiame.

in fig. lOS, and tliat of the condensers in fig 109. The steam passes through the tulics of the eomlenser, the condenser itself standing in a water tank with the water surrounding the tuhes. In fig. lOS it will be seen that tlie air pinnp stutfing-box is provided with a pipe communi- cating with tlie hot well. The object of tliis is to nitroduce water to a lantlioi'u bush inserted in the packing, tlins preventing air leakinfT into the pump through the stuffing box. Each engine actuates a double line of pump rods liy means of a pair of quadrants, as indicated hi Plate VI 1.

rU-h'iul Frame (fig. 101).— This frame is built of steel. It has a total I20 PUMPING MACHINERY. heigtt of 101 ft. Over the winding pulleys are placed girders for carrying the capstan pulleys. The winding pulleys are 17 ft. and the capstan pulleys 5 ft. in diameter. Each capstan pulley will carry 30 tons.

Fig. 10.5. Fio. 106. Fio. 107.

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is placed a 30-ton steam At each end of the winding engine house lowering the pump work. capstan for the purpose of lifting and pit-head frame for leading Guide pulleys are fixed on each side of the pulleys. the capstan rope to the overhead .S/ia/t-Each engine is provided with a pair of System of Sinking the TYPES OF MINING ENGINES. 121 122 PUMPING MACHINERY. sinking pumps, each 300 ft. long, for the purpose of sinking in stages of 300 ft. the On completion of the first stage, plunger pumps are put in to take the place of the sinking pumps, and then the sinking pumps are used for another stage of 300 ft., when the operation of putting in plunger lifts is repeated.

Sinking Lifts. —Each pump is 23 in. in diameter, has a 12-ft. stroke, and is suspended in steel rods as in fig. 110.

That the sinking pumps may stand clear of the plunger lifts, they are worked from a set-off on the mahi rods, as in figs. Ill and 112, and in detail in fig. 113. In the shaft above the sinking lifts are placed steel girders, from which the sinking pumps hang in the suspending rods, the top of the suspending rods being provided with screws, as shown in fig. 114. The screws are made long enough to allow of an addition of a length of pipe; the screws have nuts on which are fixed worm wheels gearing into worms, actuated by means of Pelton wheels taking their power from the water column, as in fig. 1 15. The lower girders are for

Fig. 109. —Details of Surface Condenser. 2400 square feet of tube surface. Number of tubes, 954. taking the weight when it is required to add an additional length of rods. The Pelton wheels are shown in section in figs. 116 and 117. It will be seen that there are three wheels on one shaft. The two outer wheels are made to run in one direction for lifting and the centre wheel in the opposite direction for lowering. The general arrangement of the Pelton wheels for three sets of sinking lifts is given in fig. 118, and a side view of the screws in fig. 115. Plunger Lifts.—A plan of three pairs of plunger lifts showing the positions of the sinking lifts is given in fig. 119, tod an elevation in fig. 120. That the plunger lifts may be all in a line, one under the other, steel side rods are carried down from the plunger head and connected to the pump rod directly underneath, as in fig. 120, and also shown in figs. Ill and 112, together with the suspending rods for the sinking lifts. Pump Rods. —The pump rods are 22 in. square, built up of four 11-in. square timbers, and are guided every 45 ft., as in fig. 121. The catch-pieces and banging beams between each plunger set are shown connecting the bucket in fig. 122. The method adopted for rod to the main rods is illustrated in fig. 113. TYPES OF MINING ENGINES. 123

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126 PUMPING MACHINERY.

Underground Engines and Pmnps.- -There are various kinds of engines and pumps used underground. In the early days of underground engines, the author had occasion to put a pair of engines and pumps at the bottom of the pit at the Clay Cross Colliery, and an experiment was then made to ascertain the Spear loss from condensation in the steam Square pipes. 3" {gj "poi shaft ft. 4-=+-=. The was 1000 deep, and 3- im=im the boilers were on the surface. The following are the results of the experi- 3* ment.

Result of experiment to ascertain J- \ KM the loss caused by taking steam down

: CM , ^ a coal pit z lOI < \o\ Diameter of pipes, HI* #=^ 3- K>t^=:^

K>n 9¥ S^ /(VnmJ— \lti0l %gtiS

Fig. 113. —Detail of Spear Rods show- ing connection for rods of sink-

ing lifts. TYPES OF MINING ENGINES. 127

with steam-moved valves, single and compound, but with various combina- tions of steam cylinders and pumps to suit the various conditions of application, and with various contrivances for giving motion to the valve

of the steam cylinder; the object of the design is frequently to produce a compact and cheap pump. These are made single and compound, condens- ing and non-condensing, and two engines and pumps are often combined on

-41

Fig. 114.- -Detail of Bump Rods showing lowering rods and screws

for sinking lifts. the duplex plan of steam valve motion described in Chap. XI., fig. 191. For the purpose of making these pumps cheap and self-contained, they have a short stroke. Where compactness is a great consideration a short stroke pump is useful, but as all non-rotative engines and pumps must have considerable clearance in the steam cylinders, the longer the stroke the less the percentage loss from clearance. Where the work to be done is considerable and permanent, a long stroke is to be preferred for non-rotative engines. There is no difficulty in 128 PUMPING MACHINERY. arranging long stroke engines on the duplex plan— that is, in having two complete double-acting engines and pumps with the valve motions so arranged that when the two engines are working together one engine commences its stroke before the stroke of the other is completed. At the same time, each engine may have its valve gear so constructed that in the case of accident to one engine the other may be kept at work. This is superior to the usual duplex engine, which consists of two complete engines and pumps mutually de- 2'' pendent on each other. If 1^ I — O''^ *1 one engine is out of order, neither can be worked. On the question of compactness the ordinary duplex pump may be desirable for small powers, but for large powers other designs and arrange- ments are to be preferred. Dip Worldngs. — The dip or inclined workings in mines are sometimes drained by means of steam pumps, and as the pumps have to be moved from time to time, the short- stroke self-contained pump

is convenient. The author has recently

met with a case where all

the water of the mine fol- lowed the workings to the

' dip.' The shaft was 500

ft. deep and provided with a Bui'face engine and shaft pumps. The workings ex- tended from the bottom

of t||e mine to the dip,

a distance of 3000 ft., Fig. 115. -Arrangement of Pelton Wheels and Lower- with an inclination of 1 ing Gear for Sinking Lifts. in 10.

Steam pumps of various types, simple and duplex, etc., were used to pump the water from the workings up the incline to the main sump. The total length of steam pipe was about 4000 ft., and the average consumption of coal per pump H.P. for all the steam pumps was 30 lbs., and as the boilers evaporated 6 lbs. of water per lb. of the slack coal used, the con- sumption of steam per pump H.P. for the system (including all losses of TYPES OF MINING ENGINES. 129

Fia. 116. Fig. 117.

Figs. 116 and 117. —Details of Pelton Wheels for working worm and screw gear for

lowering and lifting sinking lifts.

Fig. 118. —Plan showing Pelton Wheels and Lowering Gear for sinking pumps.

9 —

I30 PUMPING MACHINERY. condensation in steam pipes, etc., anaounted to 180 lbs. The wort done was about 200 H.P. This clearly was a case where hydraulic transmission of power from the surface would effect a great economy. Rotative Emjines Underground. —For permanent work underground various forms of rotative engines are used.

^ia5l-r^J^^;^»W,w>V.«<.Aiv

Fig. 119. —Plan of Plunger Lifts showing position of sinking lifts.

The type much used in France and Germany is the ordinary cross com- pound engine with double-acting plunger pumps.

The following are particulars of examples of such engines : Underground Puminng-Engine at the Hugo Mine, Westphalia.—Depth from surface to engine, 652 yards; distance from pit bottom, 280 yards. TYPES OF MINING ENGINES. 131

The engine is of the horizoTital cross compound type, having two cylinders.

Attached to the low-pressure piston rod is a double-acting plunger pump, and attached to the high-pressure piston rod by means of a three armed lever are two plunger pumps employed to raise the water to the feed

Fig. 120. —Elevations and Plan of Plunger Lifts.

cistern, a height of 45 ft. The steam from the low-pressure cylinder and the jackets is condensed by the water lifted by these pumps. The diameter of the high-pressure cylinder is 27-55 in., and of the low-pressure 45'27

in. ; the length of stroke is 47-24 in. ; the capacities of the cylinders are 132 PtTMPING MACHINERY.

in the ratio of I to 2'75 ; the diameter of the main plungers is 7'55 in.,

and of rod 3 '93 in. The rising main is 9^ in. inside diameter, with a total length of 1027 yards, the vertical rise being 641 yards. The steam pipe is 9^ in. in

internal diameter, 1100 yards long, and is carried down the pit and along the connecting gallery side by side with the rising main. The steam pipe

' is covered with a layer of infusorial ' earth ^ in. thick, over which is laid 1-j^ in. thickness of paper pulp, and that has a covering of jute canvas lapped with galvanized iron wire with a double coating of sheet iron and lead,

^ 1

Sh ATT i: -OWlOtx^lO .or^c m

Q — — —

TYPES OF MINING ENGINES. 133

conducting coverings, the loss by condensation is very considerable, being 22-4 per cent, of the total steam supplied. The coat of the tv^o engines and the necessary underground works was

as follows :

Cost of engines, rising mains and steam pipes, . . £12,000

Buildings and proprietary works underground, , . 5,779 15

Total, . . . £17,779 15

The engine when making 40 revs, per minute lifted 960 tons of water in a shift of eight hours at a total cost of

Steam, ...... £1 14

Wages, ...... 068

Lubrication, . . . . .033

Lighting and current repairs, . . .071

Total, . . £2 11

for 960 toils of water lifted 1968 ft.

It will be seen that the cost of the whole installation was about £60 per effective H.P., without boilers.* Combined Direct-acting and Rod-pumping Engines. —At Arsimont, in Belgium, the drainage engines are required to lift a quantity of water varying from 1800 cubic metres per day in summer to 4000 or 5000 metres in wet winter. This has to be raised partly from 203 metres, and partly from 260 metres, but ultimately tlie lower level will be extended to 350 metres. To meet these conditions, two compound horizontal engines have been placed at the 260 metre level, each driving four plunger pumps, which force the water to the surface, while a part of the power is transferred by spur gearing from the fly-wheel shafts to a pair of Rittinger telescopic pmnps placed in a vertical shaft below the engine chamber, now 17 metres deep, but which will ultimately be carried down 90 metres more to the full depth of 350 metres.

The principal dimensions of the engines and pumps are as follows :.—

A. Bittinger Pumps in Pit. Diameter of plungers, ..... 0'495 metre. 1-200 Length of stroke, .... ,, Capacity per stroke, . . . . 0'232 euhic metre. '600 Diameter of suction pipe, ... . metre.

Diameter of rising pipe, . . . 0'600 ,, Velocity of water in rising pipe at 30 revolutions or 10 0'860 strokes per minute, ..... ,,

* Proc. Inst, of Civil Engineers, vol. cxviii. p. 515. —— —

134 PUMPING MACHINERY.

B. Steam Engities. Diameter of H.P. cylinder, ... . 0-600 metre. Diameter of L.P. cylimler, . . _ 1-000 Stroke of pistons, . . _ O'SOO Length of receiver, . _ 2-150 Diameter receiver, of . ... 0-400 Diameter of fly-wheel, .... 3-500 Diameter of steam pipe, external, . 0-200 Number of expansion joints in 250 metres, . . 3 Diameter of exhaust pipe when working high pressure, 0-095 metre. C. —Condenser.

Diameter of air pump, . ... O-.'iOO Length of stroke, ..... 0-320 Capacity per revolution, .... 0080 cubic metre. D. Force-pmnps of Engines. of lift Height above engines. . . 250 metres.

Height lift . of above sump, . . . 268

Diameter of plungers, . . . 180

Length of stroke, . . . OSOO Theoretical discharge of each engine per 24 hours at 30 revolutions per minute, . . . 2-733 cubic metres. E. Rising Pipes. of Diameter discharge pipes in the engine-room, . . 0-200 metre. Speed of water per second at 30 revolutions, . 0-970 Diameter of large air vessel, ..... 0-700 Height, ...... 6100

Thickncis of casting, . . . . 0-040 Diameter of rising pipes in up-cast pit, 0-280, 0-290, and 0-300

Thickness ,, ,, 0-030, 0-025, and 0-020 Velocity of water in main from the two engines at 30

revolutions, . . . 0-260

The results obtained at the regular working speed of 30 revolutions

were : Effective discharge of the pumps, .... 974 per cent. Water lifted by both engines in 24 hours. 6 -3 18 cubic metres. Steam consumption at boilers per useful H.P. per hour as

determined from the discharge, . 16-2 kilogrammes. Total condensation per hour= 450 litres, 12 per cent. Pressure of steam in the boilers, 5 atmospheres. Pressure of steam in the steam drier in engine-room. to 4f 5 ,,

Vacuum in condenser, . . .. O-760 metre.* On a High Lift Underground Pujn,f>ing- Engine. —The engine has a single horizontal cj'linder 0-75 metre in diameter, and a O'SO metre stroke

provided with Meyer expansion gear adjustable by hand. The initial steam pressure ranges from i\ to 3-| atmospheres effective, and the cut-off from ^ to \ of the stroke. The pumps—two siiigle-acting plungers 110 millimetres in diameter, placed back to back—are in line -with the steam pistons, and are connected with it by a cross-head, which also drives two small and heavy flj'-wheels placed behind the steam cylinder.

* Proc. Inst. Civil JUiiyiiicers, vol. cvii. p. 515. —

TYPES OF MINING ENGINES. 135

The slide-valve is driven by an eccentric on the fly-wheel and the expansion valve from the cross-head. The cast-iron framing is exceedingly solid, the dimensions having been calculated on the supposition that it is a beam supported at the ends, and loaded uniformly through its length in order to render it independent of movement on the ground.

The condenser, with its air-pump of 0'260 metre diameter, is placed on one side of the engine. The whole of the water to be lifted passes through the condenser, and is delivered under pressure to the suction valve of the main pump.

The useful eflfect realised by the engine and pump combined varies from 71 to 77 per cent, of the power expended, as determined by experi- ments made in September 1888, when the pump valves had been at work five months without being changed. The principal results of these trials are contained in the following table :

No. of Experiment. 136 PUMPING MACHINERY. over the shaft, and imparts motion to a single line of spear-rods for working the pumps. The inner, or low-pressure, end of the beam is made to form a balance-box.

The high-pressure cylinder is 60 in. in diameter, with a stroke of 6 ft., and the low-pressure cylinder is 110 in. in diameter, with a stroke of 12 ft. The ratio of the cylinders is thus 6'7 to 1. The stroke of the pumps is TYPES OP MINING ENGINES. 137

equal to that of the large cylinder— 12 ft. ; the pump plungers are 23 in. in diameter, the first plunger set being placed at a depth of 700 ft. from the surface. The engine is designed to raise 1500 gallons per minute from a total depth of 1550 ft. To raise this quantity the engine will work at seven strokes per minute ; the actual horse-power being 730. The water-load on the engine, all referred to the large cylinder, is equal to

30 lbs. per square inch. This load is practically double that of the proper

Fig. 124. —Compound Cornish Engine, Wailii Mine. load of the old single-cylinder Cornish engine, which, to give the same power, would necessitate having a cylinder 156 in. in diameter. It may be of interest to note that the rocking beam, which is built up of mild steel plates and angles, with massive cast-iron centres for the shaft and pins, is 48 ft. long over all, and 8 ft. deep at the centre and along the parallel part ; the two bearings of the centre shaft are each 22 in. in diameter by 24 in. long. The rocking beam with centre shaft and pins weighs 50 tons, and the plummer-blocks and sole-plates another 14 tons.

The large cylinder, as already noticed, is 110 in. in diameter; it is 138 PUMPING MACHINERY.

^iSi -^--^ ^ Irai

Fig. 125.—Plunger Pump, Waihi Mine, 700-feet lift. TYPES OF MINING ENGINES. 139

15 ft. 4 in. long over the flanges, and ^ in. thick, and with bedplate and cover weighs 41 tons. The pistons and piston-rods of both cylinders have naetallic packings. The cross-head guides are supported on the rocking- beam floor, and are constructed so as to allow for expansion or for

I'lG. 126. — Differential Gear, Waihi iline. any slight deflection of the cylinder girders, to which they are attached at the top.

The condenser and air-pump are placed in a sump at the side of the engine-house, as shown in fig. 123. The air-pump is placed vertically, 140 PUMPING MACHINERY.

and is 30 in. in diameter, having a stroke of 5 ft. It is worked from the rooking beam.

The condenser is of the surface type. The tube-plates are 5 ft. 6 in. in

diameter, of rolled brass ; there are 954 brass tubes, 1 in. in diameter

externally and 10 ft. long, giving a surface of 2400 ft. The whole of the

Fig. 127. —Compound Cornish Engine, South StaiTordshire Mines Drainage. outside surface of the tubes is exposed to the water in the sump, The water from the mine pumps is discharged through this sump.

The plunger pump is illustrated in fig. 125. The plunger, 23 in. in diameter, is worked in a direct line with the spear-rod, which is carried down past the plunger case by two mild steel side-rods, from the massive cross-head at the plunger head, and attached to the spear-rod below the pump. By this arrangement the old method of working the plunger by a set-ofF from the spear, with its consequent excessive side strain, is avoided. TYPES OF MINING ENGINES. I4I

The pump is fixed at a depth of 700 ft. from the surface. The valve-boxes and pipes are placed in a chamber at the side of the shaft. The connecting pipes and the rising main are 21 in. in internal diameter. There are three suction and three delivery valve-boxes, each having a 12-in. cast-iron double-beat valve with gutta-percha beats. The plunger case and the

rising main, weighing together 160 tons, or, with the water-load in addition, 280 tons, are carried on two massive built-up steel girders, firmly built into the sides of the shaft. The side-rods connecting the spear-rod, above and below the pump, pass down between these girders.

The engine is governed by the Davey differential gear of the latest form. The engine cylinders are provided with five double-beat drop- valves of gun-

metal ; one steam and one equilibrium for the high-pressure cylinder, and one steam, one equilibrium, and one exhaust for the low-pressure cylinder. Fig. 126 shows the differential gear and the method of conveying the motion to worlt the high-pressure valves. When the main pistons and the rocking beam of the engine are at the end of the stroke, then the

piston of the small subsidiary cylinder E of the differential gear is also at

the end of its stroke ; all the double-beat valves for actuating the engine, steam, equilibrium, and exhaust are then in a closed position. The tappets on the rod H for actuating the high-pressure steam and equilibrium valves, and the tappets for the low-pressure valves, are then adjusted until they are in contact with the dies on the various levers through which the valve-rods pass, so that the least movement of the subsidiary piston of the differential gear will open the valves. All adjustments for varying the cut-off on high-pressure and low-pressure

steam and equilibrium valves is made by varying the travel of the roller

levers. These roller levers have the engine motion, which is conveyed through the shaft F and the tappet rods H, J. For the earliest cut-off the

tappet K is screwed against the die L, so that the roller M begins to move at the commencement and continues to move throughout the whole of the engine stroke. For a later cut-off the tappet K is moved further up the

rod, so that the roller movement is delayed and its travel shortened, the

effect being that the valve is dropped later in the stroke. CHAPTER VII.

PIT-WOKK.

The term ' pit-work ' is employed to designate the pumps in the shaft and all that appertains thereto—pump rods, guides, shaft timbering, etc. Pump rods are usually of red pine having a tensile strength of from

12,000 to 14,000 lbs. per sq. in. After making all allowances for the weak- nesses not generally detected in large baulks of timber, and giving a proper factor of safety over and above the maximum strains to which such rods are

exposed, the working load should not exceed 500 to 600 lbs. per sq. in. in main rods. Higher strains are employed when there is a good practical

reason for keeping down the size, as in bucket pumps where the size of the

rod is limited by the size of the pump. Iron or steel rods are used for

bucket lifts, sinking lifts, etc., but the main rod of a large pumping-engine should be of wood. Iron and steel rods have been used both in the solid and in built-up forms, but such rods have not generally found favour. The

joints are apt to work loose,

and the practical difficulties

of effecting repairs is very

coupunc& of wrought iron pump rods. great. Fig. 128 represents a form of wrought-iron or steel- Fig. 128. rod coupling used in Ger- many, and also in a few cases in this country. Steel rods have also been used in an inclined shaft, as shown in fig. 129. The alternating bending action from the weight of the rods, togethir with the loosening action of the alternating strains, caused the rods to fail. Pump rods built up of girder sections, sometimes of the box form, have been used, but it has been found that there is a great difficulty in keeping the joints from working loose. Iron and steel rods of all forms, where they are subject to alternating tensile and compression strains, are subject to greater vibrations and derangement than wooden rods. The rods should be heavy enough to overcome the resistance of the pump so that there may be no thrust on them from the engine during the down stroke.

When the double rod or balanced system of pump rods is employed, it PIT-WORK. 143

W g

Ph M 144 PUMPING MACHINERY.

is usual to make each rod at least 20 per cent, heayier than the water load.

When single rods are used, as with the Cortiish engine, the surplus

Engine here.

Fio. 130. —Cornish Pit-work showing front and side elevations ol pump work, rods and balance bobs for the entire depth of shaft. weight of the is often greater is rod much ; the surplus then taken up by balance bobs, one being placed on the surface where nice adjustments can PIT-WORK. 145

easily be made by putting on or taking off weight. In a great length of rods, other balance bobs, placed underground, are sometimes found necessary. An example of the

Cornish system of pit-work is given in fig. 130. In this system the

sinking lift is used for a depth of

30 to 40 fathoms ; then a plunger pump is put in at that depth, and

the sinking lift used for a further

depth ; and so on. A detail of the

sinking pump is given in fig. 131,

and of the plunger pump in figs. 132 and 133.

For a lift of not more than 40 fathoms leather-faced flap valves may be used both in the sinking and plunger pumps, but much higher lifts liave been made possible by alterations in the form of the pumps and the use of double-beat and other types of valves in the place of the old Cornish type. The jointing of the rods should have careful attention. Splice joint- ing is not to be recommended.

There is nothing better or more easily constructed than butt joints. The ends should be carefully

' squared,' and the bolt holes for the strapping plates bored with a little 'draw,' so that when the bolts are all tightened up the ends of the rods may be drawn together. Butt joints are easily tightened by wedging should they become loose.

There is less vibration with wooden rods than there is with iron or steel ; the wood being so much larger in section for a given strength is in a better proportion for the function it has to perform, viz., that of lifting the water by

lO 146 PUMPING MACHINERY.

Comiah Plunger Pump witli Double-beat Valves and Ciicular Doors,

Fio 133 Fro, 132. PIT-WORK. 147 its own weight, and in working subject to alternate compression and tensile strains. During the down stroke the engine should not put any thrust whatever on the rod. If it does, then unpleasant buckling and vibration will occur. The rod should hang on the pin of the beam or quadrant with considerable weight during its descent, therefore it must be heavier than is re- quired to merely overcome the resistance of the plunger. Wood rods require less staying than S iron or steel. It is usual to make each length of rod 50 ft., placing a stay in the middle of each length. Each joint is made with four strapping plates of mild steel. It was the custom to make the plates of hammered iron and to taper them so that they might have the greatest strength where most needed, viz., in the centre, but parallel plates a of mild steel are now usually employed. s tn Rubbing-pieces of hard wood should be a fastened on the four sides of each rod "5 s where the guides occur. br: Attempts have been made to form the pump rod into a rising main, thereby economising space in the shaft. A pump constructed on this plan

(shown in fig. 134) has been erected in the north of England, but we have had no information as to its efficiency. We fear, however, that the practical diffi- culties of applying the system satisfac- torily to heavy pumping will be found to be very great. In inclined shafts rods are carried on iron rollers. An example of pit-work in an inclined shaft is given in figs. 135 and 136. The machinery includes a pumping engine, a man engine, and a capstan engine, — the relative positions of the engines at the head of the shaft being shown in plan in fig. 136. The first 423 ft. of the shaft is vertical, and the remainder inclined at an angle of about 60 degrees with the horizontal. 148 PUMPING MACHINERY.

S p. -a c

8 E

K PIT- WORK. 149

Tlie man engine and the capstan are driven by an engine having a pair of cylinders 1 1 in. in diameter and a 20-in. stroke. On the crank-shaft of this pair of engines is a pinion gearing into a spur wheel on a counter shaft, this counter shaft also carrying a pinion gearing into a spur wheel on the capstan drum shaft, and a spur wheel gearing into a large spur wheel carrying a crank pin, from which tlie rod of the man engine is operated. Tlie capstan drum is 6 ft. in diameter and 5 ft. 3 in. long, running at the same speed as the man engine. It is adapted for lifting a load of 5 tons.

The man engine has a single line of rods balanced as shown in figs. 135 and 136. The rods have a stroke of 12 ft., and make five strokes per minute. In ascending or descending the men step alternately from the stands carried by the rods to fixed stands at the side of the shaft.

It will be noticed that the balance quadrant is placed next the engine, so that the horizontal spears are in tension ; this is also the case with the pumps. The rods are made to run on rollers. Both the capstan and the man engine can be thrown out of gear. The pumping machinery consists of a compound differential pumping- engine, actuating three plunger pumps in a line, one below the other. The engine has cylinders 26 in. and 46 in. in diameter respectively, with an 8-ft. stroke, making eight doable strokes per minute, at which speed the pumps will raise 150 gallons per minute. It is worked with steam at

50 lbs. pressure. The total vertical height of 2211 ft. is divided into four lifts, the bottom pump being a bucket lift. The plunger pumps are of the con- struction shown in fig. 137. These pumps have plungers 8|- in. in diameter, covered with gun metal. The valves are double-beat, and are also of gun metal. A large example of inclined pit-work is to be found at the Lindal Moor Mines. The shaft is inclined, but quite straight, having a vertical height of 600 ft. in an incline 1000 ft. long. The pump rod is 24 in. square, the section being built up of four 1 2-in. baulks. It runs on rollers, and at the bottom, attached to the end of the rod, is a plunger 30 in. in diameter, having a stroke of 10 ft. The vertical height of the lift is 600 ft. Height of Lift. —As before intimated the possible height of the

plunger lift has been greatly increased by improved construction of pump. The Cornish H piece is very weak in form, and the flap valve is unsuited to heavy pressures. The modern form of pump is that illustrated in Chap. VI., fig. 120. To accommodate this form of pump it is necessary to make an excavation in the side of the shaft to receive the valve boxes and the suction tank. The only working parts of the pump standing in the shaft are the plunger and plunger barrel. If the pit has already been sunk, it is easy to determine what length

the lift should be, because it is quite practicable to use lifts as high as ISO PQMPING MACHINERY.

800 to 1000 ft. with safety. Lifts of over 800 ft. have been largely in use

for many years. If, however, the pit has yet to be sunk, then it is a question the consideration of which must be governed by the special circumstances of the case. The system of permanent pumping may be determined by the selection of the system of sinldng. In the Cornish system a plunger is needed every 40 fathoms, but by employing two sinking pumps, one in advance of the other, a depth of 80 fathoms can be

accomplished before a plunger is put in ; greater depths can be covered

by specially designed bucket lifts ; such lifts have been used for 300 ft.,

so that tvFO sinking lifts would cover a depth of 600 ft. Temporary

Fig. 137. —Details of Plunger Lift, Rods, and Connections, as fixed in the inclined shaft indicated in figs. 135 and 136. steam pumps are often placed in recesses in the side of the shaft during the sinking operations, and retained there for emergencies after the com- pletion of the pit. Steam pumps are also suspended in the shaft to take the place of sinking lifts. These are questions for the consideration of the engineer having a knowledge of the local circumstances. Sinking pumps are suspended by rods, chains, wire rope, blocks, or by wooden rods. For heavy pump work, steel rods and lowering screws, as illustrated in Chap. VI., should be employed. A powerful steam capstan is also required for lifting and lowering the pump work and putting it in position. It is advisable to have the permanent pit-head gear erected before the sinking is commenced. Mt-work. 151 fpm 152 PUMPING MACHINERY.

An example of large modem sinking and permanent pumping plant is fully described and illustrated in Chap. VI.

Bucket Lifts for Sinking Purposes.—The Cornish bucket lift is illus-

FiG. 139. —Double Beat Pump Valve as used in plunger pumps of mining pumps.

of to trated in fig. 131 ; it is used for depths 30 40 fathoms. The suction pipe is provided with a sliding wind bore, the bottom of which should be made very strong to resist the eflfects of blasting. Wooden plugs are ;'

PIT-WORK. 153 driven into the upper holes, where necessary, to keep down the level of the water in which the men work.

Another device is that of carrying down the suction pipe inside the ' wind bore nearly to the bottom. The wind bore is suspended by a pair of blocks, and lowered as the ground is excavated. When the sink- ing lift itself is suspended in lowering screws, the sliding wind bore is some- times dispensed with, but it is generally useful to have it. The working barrel should be made much longer than that necessary for the stroke of the pump ; it may then be lowered some distance whilst at work without the bucket coming out of the barrel.

The suction valve box is provided with a door-piece of sufficient size for easy examination and removal of the valve and seating while above the working barrel a similar door-piece is provided for examination and removal of the bucket. Originally these door-pieces were made square with flat doors, and for small pumps and light pressures the design is not particularly objectionable, but the modern form of door-piece is globular with a circular door (fig. 138), thus secur- ing greater strength. Fig. 140. —Suction Valve Seating held in position by means of a Weight hanging below. 154 PUMPING MACHINERY.

Where clack doors are used, a safety clack piece is often provided above the door-piece, the valve of which can be drawn by means of fishing tackle from above, for use in the event of the water rising so fast as to prevent the pitman from putting the door in place, as shown in the

Cornish bucket lift (fig. 131). The old plan was to secure the valve seatings in their places by making

' them taper, and u inding thick cord around them, or gearing ' them with leather like that of a bucket. Taper seatings have often given great trouble by seating themselves so firmly that rods and screws have been required for the purpose of drawing them. Sometimes the seating loop

breaks under such strain, and the lift has to be taken out bodily : to meet such contingencies the supports of the lift should be so placed as to allow the lift to be raised bodily by screws or capstan. For heavy pumping it is not advisable to have taper seatings, but to construct them in the manner shown in fig. 53, Chap. III. This seating can be drawn by means of fishing tackle attached to a wire rope. Various kinds of fishing tackle are in use.

A more detailed plan of keeping the valve seating in place without the taper fastening is shown in fig. 140. It will be seen that any tendency to rise is resisted by the weight attached to the spindle, also by the tendency to cause a vacuum under the weight. For heavy pumping a stronger form of valve and box than that shown in connection with the Cornish pit-work (fig. 131) is required; double- beat valves (fig. 139) are then used. The single-flap and double-flap or butterfly valves are less liable to become permanently 'gagged' by bits of wood, stone, etc. Special care is needed to exclude gags when double-beat valves are employed. With small sinking pumps flexible suction pipes are used, aud sometimes several suction pipes are attached to the same pump, so that more than one pool in the shaft bottom may be commanded at the same time.

Pulsometers are also used as pilots to sinking lifts.

For heavy pumping it is not generally advisable to have buoket- door-pieces of the size necessary for removing the bucket and valve seating, because of the great weight and space occupied. The lifts should be so arranged, when possible, that head-room is provided sufficient for drawing the rods bodily out of the lift by the ^eam capstan, and then a fishing tackle lowered by a rope is used to bring up the valve and seating. CHAPTER VIII.

SHAFT SINKING THROUGH WATEK-BEAEING STBATA.

Bailing Tanks. —There are various ways of dealing with water in sink- ing shafts, and where the quantity to be dealt with is small the difficulties are not serious, but the problem how to deal with large quantities economi- cally and expeditiously is a matter of some difficulty. The actual sinking of the shaft has to be considered in connection with the pumping apphances. The space available for the pumping arrange-

ments is often very limited after sufficient space has been allowed for the minuig operations. The shaft may have to be lined with tubbing ; these and other circumstances, general and local, require consideration.

When the quantity of water is small, it is frequently dealt with by the winding engine. The kibbles for raising water (fig. 141) have a valve in the bottom which may be lifted by a hand lever for discharging ; or the valve may be opened by lowei-ing the kibble on to the discharging trough on the top of the shaft. An ingenious form of bailing tank (fig. 142) has been used. The tank & is a cylinder with a piston a, and a foot valve, the piston being attached to the winding rope, and the tank lowered into the water at the bottom of the shaft. The piston descends to the bottom of the cylinder when the tank has been lowered, and rests on the bottom of the shaft. On the tank being drawn up the piston first rises till it comes to a stop at the top of the tank. During the rise of the piston, water has been drawn in through the foot valve, and the tank is drawn up to the surface with the water in it. The water is then discharged by lowering the tank on to the discharge launder, wliere a provision is made for lifting the foot valve. Thus the filling and the emptying of the tank is done auto- matically. Large bailing tanks are used with special arrangements for

filling them, such as pulsometers, steam pumps, etc. Bailing tanks may be used to raise tlie water to the surface, or to a point in the shaft where pumps have been provided. The water in the upper strata may be caught by ring dams or other methods, and pumps placed there to prevent the water falling to the bottom of the shaft. The water thus caught may be dealt with by temporary or permanent pumps, 156 PUMPING MACHINERY.

the method adopted being governed by the local and special circumstances of the case. Bailing tanks are sometimes hung in the shaft, into which winding tanks are lowered by the winding engine. The suspended tanks are provided with filling appliances, such as pulsometers, steam pumps, etc. The arrangements for discharging the winding tanks or kibbles are various ; a

running platform which is run in over the shaft and under the tank may

Fig. 141. —Mining Kibble with valve in Fig. 142.—Cylindrical Tank with bottom for use in winding water. piston and valves for bailing water. be used. The platform forms a discharging launder for the water. This is a convenient and safe arrangement. Tipping appliances have also been used. • Professor Galloway has designed special tank appliances for winding water, used in unwatering a pit in South Wales. The mechanism and the results obtained are described in detail in the Transactions of the Federated Institution of Mining Engineers, vol. xiii., from which we have derived the following information. There are two water tanks in the positions of ordinary winding cages provided with wire rope guides. Automatic appliances fill and discharge the tanks. One of the tanks is showu at A (fig. 143). In the bottom of the tank are fixed two flap valves, opening inwards, SHAFT SINKING THROUGH WATER-BEARING STRATA. 1 57

and attached by rods to the levers D D. The filling of the tank is effected by simply lowering it into the water in the shaft. On the tank reaching

the surface, the levers D D come into contact with levers C C (fig. 134), to which are attached weights sufficiently heavy to open the valves. The

tank in this position is ready to discharge its water into two shoots, one on each side of tlie shaft. To conduct the water to these shoots, the

bottom of the tank under the valves is provided with inclined shoots,

Fig. 143 Fig. 144.

Figs. 143-145. — Galloway's Tank Appliances for winding watei.

which direct the water from the tank to the shoots at the side of the shaft, the wrater leaping over the short intervening space. Fig. 145 represents a method of using the same tanks for winding water from a tank suspended in the shaft. The tanks with all their mountings weighed about 3 tons each, and the weight of water carried by each of them was nearly 4J tons. The top of each tank was covered by a plate with a rectangular hole in it, just large enough for a man to pass through, and the position of this hole was naturally such that the rods which connected the levers to the valves passed through it. When the tanks arrived at the surface they were full to the very brim so long as when lowered they were dipping under the surface of the water in the pit. The necessary labour consisted of three enginemen working continuously in shifts of eight hours each. In addition to the enginemen, two banksmen working in shifts of twelve hours each, and one engine-cleaner by day, were employed. 158 PUMPING MACHINERY.

The principal work of the tanksmen consisted in counting the number of tanks drawn, observing when the ropes required to be lengthened, assist- ing in lengthening them, and keeping an eye upon the operations generally. The maximum number of tanks drawn was 94 per hour. Allowing 9 tanks per hour for contingencies, that is, taking 85 per hour as an average for 24 hours, the quantity and cost per ton would be somewhat as follows, when the depth of the water from the surface was 600 ft. Quantity of water raised in 24 hours = 2,040,000 gallons = 9107 tons;

H.P. 257 ; coal consumed at 10 lb. per H.P. per hour, 27 tons 10 cwts. ; duty of 1 cwt. (112 lbs.) of coal, 22,254,196 foot pounds.

Cost per Ton of Watee raised 600 ft. SHAFT SINKINO THROUCxH WATRK-BEARING STRATA. 1 59 l6o PUMPING MACHINERY. or 'H pieces,' as they are termed The distribution of metal in the design is bad, and even for light pressures the weights are excessive. The author claims to have initiated and introduced the system of pit-work now adopted for high lifts. Valve boxes are made circular and spherical instead of square and cubical, thereby obtaining a better distribution of metal, but that necessitated quite a new arrangement of pit-work.

Sinking pumps of large size are now used for lifts which do not exceed 300 ft., and plunger pumps with pump rods for lifts of 1000 ft. and more.

We will now consider the problem of sinking a shaft and providing it with permanent pumping plant. Take the case of a colliery shaft to be sunk to a depth of from 900 to

1200 ft. In permanent pumping this is not too great a depth for one lift either with underground, or surface engines and pump rods. The question is how shall we proceed to sink the shaft so that when it is completed it may be equipped with modern and approved permanent pumping plant. It could be done by the use of the Cornish system of sinking in short stages, putting in plunger pumps at each stage, and, on the completion of the shaft, erecting the permanent plant in another part of the shaft, and abolishing the plant used in sinking. A heavily watered mine should be provided with a duplicate pumping plant. A convenient arrangement is to have a surface engine with pump rods and plunger pumps capable of pumping all the water, and under- ground pumps equal to the full work, as reserve power. The underground pumps may be either steam or hydraulic. The arrangements for sinking

the shaft might then be such as are indicated in figs. 146 and 147. Let it be required to sink the shaft to a depth of 1200 ft. Sink to 400 ft.

with the sinking pumps a and b, then put in the underground pump c.

The sinking pumps may then be used for the next 400 ft., when the second underground pump d would be put in, and so on for the next stage. On

the completion of the shaft, plunger pumps might be put in as at e, and rods carried up to the surface to complete the permanent surface pumping plant, the underground plant pumping the water during that time. The sinking pumps a and h may be lowered by means of rods and screws, as described in detail in Chap. VI. • To avoid constantly lowering the sinking lifts, pilot pumps may be

used, the lift pumps being kept supplied by means of tanks.

Where the shaft is very heavily watered the sinking pumps a and b may be used side by side for a depth of 300 ft., and the remaining 100 ft. or more covered by the use of pilot pumps.

Let fig. 147 be a plan of the shaft ; then the surface engine would

actuate pump rods in the space g, and the space h would serve for the accommodation of the steam or hydraulic pipes and rising main for the underground engines, the space / being reserved for the winding cages. SHAFT SINKING THROUGH WATER-BEARING STRATA. l6l

Sinking pumps are sometimes suspended by means of spear rods and rope blocks, as illustrated in fig. 148. Steam pumps are also employed for

To Ohouhp Ch*»,

Fig. 148.— Sinking Bucket Pump suspended by means of rope blocks, sinking purposes; sections of a pump of this class are sbown in figs. 149 and 150. II l62 PUMPING MACHINERY,

Pulsometers are also used; an illustration of the ordinary form is given in fig. 151.

is The pulsometer a self-acting steam pump without pistons. It is

Fig. 149. Fig. 150.

fb^

^'

Figs. 149 and 150. —Cameron Sinking Pump. the old Savery engine, fully described and illustrated in Chap. I., made automatic and portable.

Because of its portability and handiness it is useful for all kinds of temporary work. The consumption of steam for work done is very great. Keferring to the illustration, fig. 151, A A are two vessels alternately SHAFT SINKING THROUGH WATER-BEARING STRATA. 1 63 filled with water and discharged. E E are the suction and P F the delivery

valves. K is the steam pipe from the boiler, and C the suction pipe for the water.

Steam is assumed to be coming the direction of the arrows into one of the vessels marked A and to be forcing the water through the delivery

valve F into the delivery pipe ; at the same time water is coming from the suction pipe into the other vessel A, a partial vacuum having been obtained by the condensation of the steam. On the complete, or nearly complete,

Fig. 151. —Section of Pulsoraeter.

close filling of this vessel, the valve I is forced over so as to the com- munication with the vessel which has just been discharged and admitting steam to the vessel which has just been filled. The action has thus been reversed, and the operation goes on automatically, one vessel filling whilst

the other is emptying. The choice of plant and appliances is largely influenced by the magnitude of the work, and by local circumstances. :

164 PUMriNG MACHINERY.

Fig. 152. Fig. 153.

Shaft N°\ Shall Shafb

'oJlerTujbbvn^. before. Tubbbi^ 2ollem Colliery.

Scale. 1 lo 400

'Mi

TTrti^- .SOFT GRAY MARL:?;i'

'fl^jh Gp'a V MAR L 1;;; ';S

HI .j^,V\tfli

li^'^^AR-b GRAY MARL^iSf,

"'' '-'-''jrr7.7"''i'.''i''";''' '*

j'/.'.

>>.''f-'--ii'-'':-v-':-'--.^^5Si*i??^>?;.-.^ .'••-•.'C ""WATER BEARING STRATA -:.V;y.v/-.V:;'

Figs. 152 and 153.—Sections of Shafts—ZoUern Colliery. SHAFT SINKING THROUGH WATER-BEARING STRATA. 1 65

As an example of a heavily watered pit, and the difficulties met with in dealing with the water, we have taken the following description of the methods employed at the Zollern Colliery, Westphalia, from a paper by

F[o. ir,4. Fro. 155.

Scale, I to 50.

Figs. 154 and 155. —Sections of Shaft Tubbing—Zollern Colliery.

in the Messrs T. and W. Mulvaney Proceedings of the Institution of Mechanical Engitieers, 1882.

"In this colliery, situated near Kirchlinde, and containing 3000 acres I 66 PUMPING MACHINERY. two shafts were commenced by the original company, much nearer to the southern outcrop of the marl formation than in the collieries previously described. In consequence, the thickness of the marl is only 351 ft. to the surface of the coal measures, which at this point is only about 49 ft. under the level of the sea. " This position of the shafts had the disadvantage of being nearer to the supplies of water from streams on the surface, from one of which the writers subsequently discovered water flowing regularly into the marl, which is more fissured and broken near the outcrop.

" Though the site, for the reason above stated, and also as regards its position in the colliery itself, was not well chosen, yet the plans of the colliery buildings, boilers, machinery, etc., were on a very large scale, and the boilers and engines powerful and good. The former company are believed to have commenced work about 1856, by sinking two large round shafts, 24 to 25 ft. in diameter, intended for brick walls of great thickness, as at that time applied by German mining engineers for damming back the water. These shafts were sunk to the level of the first water feeder, which was met at about 182 ft. from the surface, or about 139 ft. 6 in. below an adit which had been constructed for carrying off' the water from the pumps.

"The general section (fig. 152), and the enlargement of the bottom (figs. 154 and 156), show clearly the condition in which the writers found both shafts as sunk down to feeder No. 1 ; and figs. 155 and 157 show the manner in which they finished them, down to the feeder No. 2 in shaft

No. I., and to the feeder No. 1 in shaft No. II. This latter shaft, as mentioned below, they subsequently completed down to its present depth of 943 ft., for coalwork, pumping, and ventilation.

"It will be seen from the plan in fig. 152 that in shaft No. I. the German engineers had ten sets of pumps firmly built into the shaft, with

an enormous mass of timber framing ; according to the system of that time the wind-bores were movable, or telescopic, so that they could be removed on firing shots or changing ; and the pumps were lengthened by common pump pipes (each one lachter, or 6 ft. 10 in. in length) added on below in the shaft. Thus the space,- even in these shafts of such great dimensions, was so encumbered with timber as to render sinking, even with moderate quantities of water, a very slow, expensive, and difiicult operation. The writers have little doubt that when the feeder Ho. 1 was first met with, and even before it was widened out by the constant flow of water, it mus' have yielded 600 cubic ft. per minute. Under such circumstances, and with the inability in some of the pumps to change either buckets or clacks for packing, at the surface, it is only wonderful that the engineers succeeded, even in course of time, by continuous pumping and partially exhausting the feeder, in sinking the sump, and in preparing, as shown at bottom in the section (fig. 152), the foundation for the great walling below the first feeder. "In April 1867 the writers, having acquired the colliery, commenced preparations for recovering shaft No. I. They encountered great difficulties SHAFT SINKING THROUGH WATER-BEARING STRATA. 167

large set of pumps, 32 in. in the oommencement ; but by hanging in one the diameter, they so far lowered the water as to enable them to take out

Fig. 156.

Fig. 157.

lifts- of Shaft sliowiug suction pipes of sinking FIGS. 156 and 157.-Sectioii Zollern Colliery.

sets of 18 in., German pumps and timber, and then to hang in other large fig. diameter, as hereinafter mentioned, and as shown m 19 in , and 20 in. wedging off part of the supply of 143 /and by 30th November 1867, after — '

1 68 PUMPING MACHINERY. water coming from the horizontal cleft or fissure, they were enabled to commence cutting out the foundation for the wedging cribs, designed for the tubbing of a shaft 17 ft. 6 in. diameter. They adopted this dimension as that most suitable, according to the extensive experience they had obtained in the opening out of such large coal-fields, where the coal formation with its numerous beds is likely to reach 2500 or 3000 ft. depth below the surface.

" This size of shaft compelled the writers to cast, at their ' Vulcan Iron Works on the Rhine, tubbing and wedging cribs of proportionately increased dimensions and thickness, and of improved construction with

greater width of flanges. This caused some delay ; but though over 600

cubic ft. of water per minute was being pumped from the first feeder in

shaft No. I. (this water coming through the crevices left by the rough

wedging in the fissure), the tubbing of the upper lift above this first fissure was set and completed up to the level of the delivering drift by 6th March

1868, as shown in fig. 154.

"On further sinking shaft No. I. to the second feeder, it was found that there was such a connection between the feeders in the two shafts

that it was advisable and economical, both as to time, cost, and application of steam power, to pump the water and carry on the operations in both shafts together. "Accordingly a direct-acting 72-in. cylinder engine of 11-ft. stroke was

erected over shaft No. II. ; a Cornish beam-engine, 84-in. cylinder and

about 10-ft. stroke, at shaft No. I. ; and lastly, a horizontal winding-engine of 42-in. cylinder and 6-ft. stroke, between the two shafts, working with lay spears and quadrants into both shafts. By this means the writers

were enabled to work together nine sets of pumps, as follows ;

2 sets of 32 inches diameter.

2 ,, 21

-^ ) J * y »J )) 2 „ 18 „

1 ,, 16 „

" With these they pumped out of the two shafts 1 200 cubic ft. per minute of the water which escaped through the wedging of the natural

fissures in the marl, and completed the closure of (jjie tubbing for the first

feeder in shaft No. II. on 9th August 1868, as shown in fig. 157 ; and for

the second feeder in shaft No. I. on 15th November 1868, as shown in

fig. 155. "In the winter of 1868 further operations were suspended, owing to the want of a railway, which had been long previously agreed upon by the Cologne and Minden Railway Company, but not constructed. This sus- pension continued for the same causes until 1870, when, to ascertain what further feeders were to be expected in sinking shaft No. II., the writers had a boring carefully made a little to the west thereof. This boring gave SHAFT SINKING THROUGH WATER-BEARING STRATA. 1 69

very precisely the positions and probable dimensions of the -water-bearing fissures, which they might expect to meet in sinliing the shaft to the coal measures; and these indications, upon the subsequent sinking, proved to be correct.

" The railway company still failing to construct the branch railway, the writers were at last forced to construct, at their company's expense, a horse

Connecting Rod FROM Engine

Fig. 158. —Unwatering Flooded Colliery—Pit-head Frame for suspending bucket -lifts in shaft.

tramway along the public road from Zollern to Hansa Colliery, and sink-

ing operations were recommenced in shaft No. II. in August 187 1. Four more feeders, Nos. 2 to 5, were sunk through and tubbed off successfully to the depth of 292 ft. before the end of March 1872, and all water was so completely shut out that the remainder of the shaf<>sinking and walling to the net diameter of 17 ft. 6 in. was carried out, first to the coal

measures at the depth of 357 ft., and then to the present bottom at 943 ft. without any pumps whatsoever in the shaft. —

170 PUMPING MACHINERY.

"The quantities of water shut out by the several lifts of tubbing were

carefully measured as follows * :

Down to, and inclusive of, tiie first four feeders. 1160 cub. ft. per min. The fiftli feeder, .... 150 Tlie sixth or lowest feeder, 100

Total . . 1410

This total is a quantity of water rarely met with in shaft-sinking ; but it

Fig. 159. — Uiiwatering Flooded Colliery —Suspending Bucket Lifts showing plan of shaft and pumping quadrants. •

was shut out SO effectually in this large shaft as to enable it to be com- pleted to the bottom without pumps. "The connection to a railway was not made until 1879, up to which time only preparatory work could be carried on in opening out the colliery from the shaft ; but since then the pit has been continually worked, pro- ducing now about 750 tons of coal per day, and with very little water to

* In all cases the quantities of water were actually measured at an overflow weir, in a watercourse constructed for the purpose. SHAFT SINKING THROUGH WATER-BEARING STRATA. 171

pump. It is worked entirely through the single shaft No. II. ; but at an early peiiod a second shaft must be completed."

TJnwatering a Flooded CoUiery.— The following illustrations (figs. 158 and 159) represent the plant used by the author for unwatering a flooded

colliery and sinking it deeper, the plant being so designed that when completed it formed the permanent pumping plant of the mine. A general view of the surface of the mine after the completion of the

Fig. 160. —Unwatering Flooded Colliery—General Arrangement of Plunger Lifts showing position of sinking lifts for deepening the shaft.

plant is given in Plate VI., Chap. VI., the engine-house and pit-head frame being clearly shown. The colliery was formerly drained by means of underground steam pumps involving a very great consumption of steam, and causing great inconvenience by the excessive heat in the workings. A sudden inburst of water overtaxed the power of the pumps, and the colliery became flooded.

The shaft was 300 ft. deep, and at that level the workings existed ; it was, 172 PUMPING MACHINERY.

however, required that the shaft, after recovery, should be sunk to a depth

of 120 ft. more The problem presented was that of getting out the water and deepening the shaft with plant which might remain as permanent plant. It was decided that four 24-in. pumps should be provided to cope with the

water in unwatering the mine, and it was evident that bucket lifts were the only suitable pumps under the circumstances, but bucket lifts had not

160 -10-3

pf^ -g "^

Elevation SHEWtNC Catch Pieces ON Pump Rods

rt#

-3, '^yjff^i^m'^Mid'^^d^'M^i ?r w m Side Euevation Sectional Plan of Shaft Tmrmwm'iffmfv^W SHAFT SINKING THROUGH WATER-BEARING STRATA. 1 73

76 in. in diameter and a 10-ft. stroke, the pumps having the same stroke as the engine.

The water was pumped away till the bottom of the shaft was reached.

It was then found that one of the engines with its pair of pumps was capable of pumping all the water coming from the feeders. Plunger pumps had been provided for the permanent pumping.

Whilst the water was kept down bj' the one engine, a pair of plunger pumps (figs. 160 and 161) were put in at the bottom and coupled up by means of wooden rods to the other engine. When that was done and the plungers put to work, the other engine was stopped, the bucket lifts taken out and plungers put in their place, thus completing the permanent plant, which consisted of two pumping-engines, each provided with plunger lifts. The permanent plant was now extended to the bottom of the shaft.

The shaft had then to be deepened by 120 ft. more. The bucket lifts were now available for the purpose. The general arrangement of the pumps

and the details of rods, etc., are clearly shown in figs. 159 to 161, and need no further description.

It may be observed that the rising main is larger than necessary, but as a matter of economy the rising mains of the bucket pumps were utilised

as rising mains for the plunger lifts.

It will be seen in fig. 159 that the suspending rods for the bucket lifts were attached to a steel beam centred under the snore pipes B B. The object of this arrangement was to insure strength, not trusting to a cast-iron connection, and at the same time to insure equal tension on the suspending rods.

After the unwatering was accomplished, and the lifts became short sink-

ing lifts, telescopic snore pipes D D were made to take the place of snore pipes B B, and the suspending rods were attached to lugs E E already provided on the sides of the suction valve boxes. Doors for the con- venience of examining the suction valves and removing gags are shown at C C. CHAPTER IX.

HYDRAULIC TBANSMISSION OF POWER IN MINES.

Explanation of the Principle. —Hydraulic transmission of power in mines is becoming largely employed, especially for pumping. For that purpose it is very conveniently applied, as the natural speed of water-

pressure engines is about equal to that of the pump ; the engine may therefore be connected directly to the pump rod without the interven- tion of any mechanism. Where a natural head is available, then water- pressure engines, such as are illustrated in Chap. XI., may be employed, but the power may be obtained from a prime mover such as a steam engine, and it is that form of transmission which we now propose to discuss.

A simple form of hydraulic transmission is illustrated by the diagram

(fig. 162). The steam engine A gives motion to the piston of the water cylinder B, the ends of which cylinder are connected by pipes to the ends of a similar water cylinder C. The piston of the cylinder C is attached to the rod of the pump D. If the cylinders B and C with their connecting pipes are filled with water, and the piston of the cylinder B is moved backward and forward by means of the steam engine A, then as water is practically incompressible, the piston of the cylinder C will partake of the same motion. The piston C will in its turn communicate its motion to the piston of the pump D. By this arrangement it will be seen that the piston of the pump partakes of the same motion as the piston of the steam engine, one stroke of the steam engine producing one stroke in the pump. The connecting pipes between the cylinders B and C may be of considerable length, so that the steam engine may be on the surface of

the mine, whilst the pump is at the bottom. ^Vhen it is advisable to

run the engine at a higher speed than that of the pump, gearing is introduced between the engine A and the cjdinder B. This is known in this country as Moore's system, but the principle is an old one. It will be seen that any leakage of water from the stuffing-boxes, pipes, or pistons of the cylinders B and C, or any leakage in the connecting HYDRAULIC TRANSMISSION OP POWER IN MINES. 175 pipes themselves, will alter the relative positions of the said pistons, with the result that the pistons may strike the covers with such force as to

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fiu^£iJiai£lUi£lfA^ii/ii^/il<:>li^l:iiil^fJj^!^'^i^^^i^

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Fig. 162. —Hydraulic Pumping—Water Rod System of transmitting power fiom the surface to a hydraulic pump at the bottom of the mine. 176 PUMPING MACHINERY. cause a breakdown of the plant. It therefore becomes necessary to intro- duce a device by means of which the relative positions of the pistons may be maintained. That is done by an arrangement of tappets and valves so designed that when either piston moves beyond its normal stroke a valve is opened, allowing some water to pass from one side of the piston to the other. It will be readily seen that the system is only applicable to the working of one pump, and that when applied for mining purposes there are three pipes in the shaft—two power pipes and one rising main from the pump. In practice, small power pipes working under high pressures are employed, and the power cylinders and pumps, instead of having pistons, are provided with plungers. The diagram is only intended to illustrate the principle. Its Application at Saarbrucken. —This system was adopted in a mine at Saarbriicken about thirty j^ears ago. The mine was 306 yds. deep below the surface. The motor consisted of a double-acting horizontal high-pressure engine having a cylinder 53 in. in diameter, and a stroke of 61 '5 in. The piston-rod was continued through both covers, and connected at each end with a plunger 9 in. in diameter. The hydraulic engine underground consisted of four pressure cyhnders having rams arranged in pairs, and connected by a crosshead. Each plunger was 6 in. in diameter, with a stroke of 66 in. Between each pair was placed a pump plunger. The pressure column 5 in. in internal diameter in. thick, consisted of cast-iron pipes and 1-J- put together in 10-ft. lengths. The working pressure at the hydraulic engine was 1150 lbs. per sq. in. For the sake of regularity and safety in working a special safety and filling valve was placed on each pressure pump at the surface, consisting of a chamber with an auxiliary feed valve, a safety valve, and an air-escape valve, which were in connection with a closed cistern on a higher level, kept constantly filled with water. In setting the engine to work, difficulty was at first experienced in adjusting the relation of the stroke of the pumps underground to those above. To effect this a magnetic telegraph apparatus was used, and signals were transmitted, until the two engines were in proper relative positions. When first put to work the speed did not exce^ six double strokes per minute, the speed of the surface and underground engines being, of course, both the same, but after some time the speed was increased to from ten to twelve double strokes per minute, and experiments were then made to determine the efficiency. It was found that 25 per cent, of the work was absorbed in friction, and that the consumption of coal was at the rate of 22 lbs. per H.P. per hour. The effective work of the pumps when making 10 strokes per minute was 100 H.P. ;

HYDRAULIC TRANSMISSION OF POSVER IN MINES. 177

It appears that the engine was worked non-expansively, which partly accounts for the high consumption of coal. The difficulty of keeping the plant iu proper working adjustment, and the impracticability of working more than one pump from the surface engine, have been against the system, and although the plant was erected thirty years ago, the application of the system has not increased to any great extent.

The total cost of the plant was £5550, or, including erection, £9117,

which is at the rate of £55'5 per H.P. for plant alone, or, including erection, £91 per H.P. WorMng Results of the Hydraulic-rod Pumping-Engine at Saar- briicken. —This is a sequel to a former memoir on the same subject, giving an account of the results obtained by the engine in continuous work. The speed has been increased from six double strokes per minute to twelve without difficulty. In order to observe the working pressure upon the different parts of

the engine, five pressure gauges were used, placed as follows : —One at the bottom of the rising pipe, and two on each of the rod tubes, one at the bottom and the other at the surface below the point of attachment of the press pumps. The readings of these gauges have been plotted in the manner of indicator diagrams. These diagrams are supposed to be

correct witliin a margin of 1 or 2 atmospheres, and are the best obtain- able in the absence of an indicator capable of working imder pressures of 80 atmospheres and above. In the rising pipe the pressure was very steady, and varied only between 26 and 28 atmospheres, the change being sensible only at the beginning and ending of the stroke. In the rod tubes underground the variation in pressure was marked by extreme regularity and precision. When the pressure piston was making the return stroke, the gauge indicated uniformly 35 atmospheres

it then rose during the cataract pause with a, vibratory movement to about 78 atmospheres, which remained the normal pressure to the end of the working stroke, when it fell with corresponding oscillation back to 35 atmospheres. There was little difference in the maximum pressure between the north and south rods, the latter indicating up to 80 atmos- pheres, this difference arising from the load not being quite uniformly distributed between the two pumps. The oscillations of the gauges at the surface were somewhat greater; near the end of the return stroke the pressure rose to about 15 atmospheres, increased during the cataract pause to 30 atmospheres, and on the commencement of the forcing action of the plunger suddenly rose to 50. This pressure was maintained regularly till close upon the end of the stroke, when it fell rapidly through 30, 15, 10 atmospheres to 0. In some cases even a negative pressure was observed when, through loss of water in the tubes, a partial vacuum was formed, owing to the waste not being made up quickly enough by the auxiliary feed valves. The velocity of the column of water in the 12 178 PUMPING MACHINERY.

pressure tube was 7-6 ft., and in the rising pipes 3-6 ft. per second.* Armstrong's Method. —The ordinary system of hydraulic power trans- mission invented by Armstrong for working dock machinery consists of pumping water by means of a steam or other engine under high pressure into pipes from which the water is taken to work the machinery requiring .the power. To compensate for the varying demand for power, Armstrong applied what is termed an 'accumulator,' which consists of a large weighted plunger in a vertical cylinder in constant communication with the power pipes. The rise of the weighted plunger or accumulator was also used to regulate the speed of the steam engine employed to pump the water under the accumulator plunger, in such a way that when the demand for water ceased, and the accumulator became fully charged, the power engine was stopped by the closing of the steam stop valve. When the demand for power recurred, the falling of the accumulator would open the steam valve and the engine would again start into motion.

Davey's Modiiicatioii. —A modification of this system is peculiarly applicable to mines where the pumps are situated some distance from the bottom of the shaft, and also where the ordinary surface pumping-engine

is not applicable, or where it is undesirable or uneconomical to take steam

down into the mine. The following illustrations (figs. 163 and 164) represent hydraulic plant, designed by the author for a colliery where the ordinary systems of pumping were, owing to local circumstances, not applicable. The general arrangement consists of a compound condensing steam engine on the surface employed to pump water under a pressure of

1400 ft., and thereby made to actuate hydraulic pumps underground.

The water is conveyed by a power pipe to the hydraulic pumps in the

mine, and is returned to the surface, where it is used over and over

again. By this arrangement clean water is used to avoid excessive wear

and tear of the hydraulic engines, which would take place if they were

worked with the dirty mine water. The rising main from the pumps is taken up the shaft and made to discharge through an adit level. As the

power water is used over and over again, a little oil may be put in it for the purpose of lubricating the working parts of the power pumps and hydraulic engines. ^ The oil should be free from acid, otherwise the steel and iron working surfaces will become pitted.

In this system of pumping, nothing is required in the nature of an accumulator of power, as the work done is constant.

All that is required is a constant pressure in the power pipes, and that

is secured in this case by the employment of a steam accumulator or

regulator, shown in section in fig. 165, and also in elevation in fig 164. The steam accumulator or regulator consists of a plain steam cylinder

* Proceedings Inst, of Civil SngiTieers, vol. xliii. HYDRAULIC TRANSMISSION OF POWER IN MINES. 179 i8o PUMPING MACHINERY.

so a

a 3 HYDRAULIC TRANSMISSION OF POWER IN MINES. I»]

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182 PUMPING MACHINERY. having a piston, the rod of which is attached to a plunger working in a hydraulic cylinder in communication with the power pipes. The front end of the steam piston is in communication with the atmosphere ; the back end is connected by means of a pipe to the main steam pipe, so that the boiler pressure is maintained at the back of the steam piston, and the relative areas of the steam piston and hydraulic plunger are such as to maintain the required pressure in the power pipes.

The steam condensed in the cylinder is automatically drawn oflF by means of a steam trap. Variations in the supply to, and the draught from, the delivery pipe are compensated for, and a constant pressure maintained by the movement of the steam accumulator plunger. In ordinary working ttie variations are small if care be taken to so design the power pumps and power engines that the former supply and the latter take nearly a constant stream. That is secured by making the power pumps double-acting, coupled by means of cranks at right angles, or by the use of three plungers, and by making the hydraulic engines on the duplex plan. Fig. 164 is an elevation of the engines, power pumps, and accumulator, partly in section.

The following are the chief dimensions :

High pressure cylinder, HYDRAULIC TRANSMISSION OF POWER IN MINES. 1 83 exhaustive set of experiments with this plant, the results of which were published in Le Genie Civil, 1885, p. 81. An abstract of his report, taken from the Minutes of Proceedings of the Inst, of Civil Engineers, is here given. " This pumping-plant erected at Shuillier, Fuveau, by the Sooi^t^ de Charbonnages des Bouches-du-Eh6ne, was designed to complete the draining of the Castellare-Leonie section. " The question to be solved was : —Given a shaft already encumbered with mining plant, with two forcing pumps 20 in. and 16| in. in diameter, with wooden pump spears, beams, guides, ladders, etc., to double the power by means of apparatus occupying as little space as possible, giving a higher dynamic efficiency, and in no way interfering with the existing machinery, which was to preserve the galleries from being inundated during the installation of the new engine. " Other circumstances added to the difficulty of the problem. At the pit-mouth, on the surface, was a Bull engine with its cylinder placed vertically over the pit, also a platform and a winding engine. In short, the new installation was not to interfere in any way with the existing machinery, or with the future deepening of the pit.

" The first scheme proposed was the installation at the bottom of the pit of a direct-acting rotative engine, taking steam from boilers on the surface, or from a battery of boilers near the engine in the mine itself. In the first instance, the result must have been considerable condensation and heating of the pit ; in the second, defective installation of the boilers. "Each case required a room beyond the reach of the water, but this condition could not be fulfilled, and it was necessary that the pumps should be capable of working under water. Messrs Hathorn, Davey & Co. being consulted, proposed the transmission of power to the pumps by water, with pressure engine on the surface, and hydraulic pumping-engines at the bottom of the pit. " Like installations had been adopted under similar conditions at the mines of Mansfeld and at Saarbriicken.

" The installation may be defined as follows : —An economically working compound steam engine, forcing water at 42 atmospheres by means of two double-acting plunger pumps. At the bottom of the pit, duplicate hydraulic pumps, both worked from the surface engine pressure water pipe, and a return pipe, also a delivery column from the hydraulic pumps to the draining gallery of the mine. The top of the pit is 292-805 metres (950 ft.) above the sea-level. The draining gallery is about 60 metres lower, or 232-820 metres above the sea-level; the situation of the hydraulic pumps, 140 metres. The total elevation of the water is therefore

232-820 - 1 40 = 92-820 metres, or in round numbers 305 ft. " The work to be done was raising 7700 litres (1694 gallons) per minute.

60x70

" The motive power engine is of the compound type, having two hori- — '

1^4 PUMPING MACHINERY. zontal cylinders with an intermediate receiver and eranks at 90". The motor is calculated to supply 2357-7 litres of water per minute to the hydraulic engines at the bottom under an effective pressure of 42 atmos- pheres. The high-pressure cylinder has a diameter of 0'762 metre (30 in.), the low-pressure cylinder a diameter of 1-270 metres (50 in.), with a stroke of 0-914: metre (36 in.). The pistons are con- nected to a double rod, the front rod ending with the crosshead of the engine, the back rod connected to the plunger rod of one of the forcing- pumps. The front rods are 0-120 metre (4-72 in.) in diameter, and the back rods 0-080 metre (3-15 in.). " The forcing-pumps at the surface are two in number, and exactly alike.

The plunger of each is attached to the piston of the motor. The effective surface of the plunger is equal to the difference of the area of the plunger and the rod —that is, S = 234-752 centimetres. " The capacity created by a full stroke is

0-023475 X 2 X -91 1 = 42-9 litres. For both plungers = 85-8 „

" The water necessary for the normal fted to the hydraulic engines must be 2357-7 litres (519 gallons) per minute. " The number of complete strokes per minute with the steam pistons 2357-7 wiU be npr.Q = 27-5, corresponding to 27-5 revolutions of the fly-wheel.

Between the two engine foundations, and in a line with the fly-wheel, is the steam-accumulator or regulator, in direct communication with the forcing main. The two steam cylinders, though neither of them is steam jacketed, are joined by a cast-iron pipe 10 in. in diameter, forming the intermediate reservoir, and connecting the valve chest of the large cylinder with the exhaust of the small cylinder. The capacity of the reservoir thus formed is 640 litres.

" The relative volumes formed by the pistons in the two cylinders is

1-2-8. The cut-off in the large cylinder is fixed, and corresponds to an angle of 110°.

" The low-pressure diagram shows that the cut-off is equal to 1-09. It may therefore be neglected. The small cylinder is provided with an expansion gear variable by hand. The speed of th(^engine on the surface must be regulated to suit the speed of the hydraulic pump underground.

" As the work underground is continuous it must therefore be continuous on the surface. There must be no reservoir of work, such as is charac- teristic of the Armstrong system. An accumulator with such a reservoir of work would uot allow the engine on the surface to determine the speed of the hydraulic pumps underground ; that it should be so was a necessary condition, because the hydraulic pumps have sometimes to work under water. To render the action constant the apparatus called a ' regulator is introduced. In similar installations in America, the Davey apparatus — —

HYDRAULIC TRANSMISSION OF POWER IN MINES. 1 85 includes not a regulator, but a simple reservoir of air. This gives excellent results in working, but has the following disadvantages :

1st. Its size must be considerable.

2nd. It must have a large and considerable supply of air. The density increases with the pressure. 3rd. The bursting of this large reservoir, containing a pressure of 50 atmospheres, would cause a great explosion.

" The steam regulator is composed of two cylinders and of two pistons mounted on one rod. In the first cylinder the back surface only of the piston is subject to the action of steam. " The motive water in the pressure pipe enters the second cylinder, and acts on the piston in an inverse direction to the steam. The areas Q and 0) of the pistons are calculated, of course, to satisfy the equation /SI = Fto, / and F being the respective pressures of steam and of the water in the pipe. This apparatus is very sensitive. It serves as regulator for the compound motive power engine. The piston rod of the regulator is con- nected directly to the throttle-valve of the engine. In case of the breaking of the pressure column of water, this safety apparatus prevents all further accident. The steam regulator offers, from a practical point of view, other advantages. The effective pressure of the water in the supply pipes may be varied by simply adjusting a, reducing valve in the steam pipe supplying the steam accumulator. " The engines at the bottom of the pit are twin engines, motors and pumps working with a pressure of 42-fl5 atmospheres, and with the return water at a pressure of 15 atmospheres (corresponding to the difference of the level between the forcing pumps on the surface and the engines at the bottom—that is, 153 metres). The hydraulic pumps raise the water from 140 metres to a height of 232-82 metres to the draining gallery. The delivery per minute is 7700 litres —that is, 462 cubic metres (101,640 gallons) per hour. The stroke of the pumps is I'829 metres (6 ft.). The diameter of each pump plunger is 0'463 metre 0'102 (18J in.), the diameter of the rod being metre (4 in.). To deliver 7700 litres per minute, the two pumps must therefore make 6'4 complete strokes. The corresponding speed of the piston per second is 0-39 metre (15-6 in.). The difference of area is 0-0503642 _ 0-035200^ = 0-0151642 metre. " Trial of the Engines. —The diagrams taken at the time of the trial 29th August 1884—show considerable variation in the pressure of water at different points of the circuit. " On the surface the variations are more felt in the pump worked by the piston of the small cylinder than in those which are worked by the large cylinder. According to the diagrams the maximum oscillations correspond to variations of 35 to 54 kilogrammes per square centimetre (500 to 700 lbs. per sq. in.).

" At the time of the trial, the water pumped from the mine was not — — i86 PUMPING MACHINERY, considerable, the fly-wheel of the compound engine making only twenty- two revolutions per minute, corresponding to a delivery to the pressure- pumps of 1887 '6 litres per minute. " Each full stroke of the hydraulic engines at the bottom consumes 368'40 litres of motive water; the number, then, of double strokes of the undergroimd pumps must be

368-40 " Five strokes only were recorded ; the remainder was lost by the stuffing boxes, distribution valves, etc. The corresponding delivery of the pump was

1201-80 I X 5 = 6009 litres per minute.

"The effective work in water raised was then

100'15 kilogrammes x 93 metres = 9313-95 kilogramme metres =124-20 H.P.

" According to the diagrams the total work done by the steam pistons was Tm = 229-20 H.P. Since the useful work was

Tm = 124-20 H.P.

^=0-542 = 54-2 per cent.

" The work of the air pump in raising the condensing water to the cooling pond (an amount of work which slightly increases the efficiency) is not taken into consideration. " The Directors of the Soci^te de Charbonnages des Bouches-du-Rhone intend to make use of the installation for working, independently of the pumps described, some underground hydraulic motors. " It will be only necessary to increase the number of strokes of the com- pound engine on the surface to provide a larger volume of water under pressure, from which it will be possible to work additional pumps in the

' dip,' and also hauling engines. " For hauling, rotative hydraulic motors, with two cylinders, having cranks coupled at right angles and valves worked by means of eccentrics, will be employed.

" The cost of the installation was as follows :

Francs. Surface engines, compound engine, and forcing pun^is free on board in London, 37,036 Hydraulic engines at the bottom transport, marine insurance, 37,415

Loading and unloading, . . , . . 13,313 Cast-iron pipes (61,997 kilogrammes), and transport, 35,782

Total cost of whole installation.

Or say, £8628."

* Proc. Inst. Civil Engwieers, vol. Ixxxiv. p. 513. HYDRAULIC TRANSMISSION OF POWER IN MINES. 187

Later Improvements. — Since this plant was erected, considerable improvements have been made by the adoption of higher pressures, and

Flo 166. —Hydraulic Pumping System of transmitting power from the surface to hydraulic pumps situated at the bottom of the mine. i88 PUMPING MACHINERY. HYDRAULIC TRANSMISSION OP POWER IN MINES. 1 89 improvements in details have enabled higher speeds to be obtained both in the power engines and hydraulic pumps. By the use of higher pressure the loss from friction in the pipes is

reduced. For a given velocity the friction is not materially increased by increased pressure, therefore with higher pressures the friction becomes a smaller percentage of the total power produced. Pressures of 4000 lbs.

per sq. in. at the power pumps have been employed, which involves, of course, a greater pressure at the bottom of the mine. It must, however, I go PUMPING MACHINERY. be remembered that as the power water is returned to the power engines, the hydraulic engines [actuating the pump, work with a back pressure.

The effective pressure is therefore that produced by the power pumps minus the friction of the water in the supply and return pipes. The higher the pressure, the greater the loss from leakage through the valves of the power and hydraulic engines, and the employment of very high pressures such as 4000 lbs. per sq. in. makes it HYDRAULIC TRANSMISSION OF POWER IN MINES. I9I necessary to construct the power valve boxes of wrought steel, and

!a=B

Fig. 170. —Duplex Hydraulic Pump.

the workmanship must be of the highest class. With pressures up to

1000 lbs., ordinary materials and ordinary valve arrangements may be used. — ; ;

192 PUMPING MACHINERY.

The gross power transmitted through a 6-in. pipe with 1000 lbs. pressure would be 254 H.P. In the ordinary application of hydraulic pumping in mines the efficiency of well-designed plant should be 60 per cent. —that is to say, the work done in pump H.P. should equal 60 per cent, of the l.H.P.

of the steam engine. The actual H. P. transmitted through a 6-in. pipe is thus 152. In two or three Westphalian collieries there has recently been erected

hydraulic pumping plant, illustrated in fig. 166. A compound steam engine a on the surface pumps water at from 3000 to 4000 lbs. per sq.

in. under the pressure of air in a regulator b. The regulator consists of a plunger in communication with the power pipe, having an air cylinder c above it. In the air cylinder the required pressure is preserved by means

of the air pump d. The power water is returned to an air vessel e, from

which it enters the suction pipes of the power pumps. The power water

is clean, and has some oil added to it.

' The plant at ' Pluto Colliery is thus described :

On the surface is a twin steam engine with cylinders 870 mm. in diameter, having a stroke of 1 080 mm., by which four rams, each 80 mm. in diameter, are worked.

These rams, which are supplied with water containing some vaseline oil, force the water into an accumulator up to a pressure of 200 atmospheres from this the water is led through pipes with an internal diameter of 65 mm. and a thickness of 10 mm. of metal to the hydraulic pumping- engine, standing at a depth of 505 metres below the surface. This is a double-action twin engine without revolving parts. The driving gear is so constructed that in the water column there is no pause in motion, whereby, notwithstanding the 250 atmospheres pressure, all blows are completely avoided. The motor pressure water is forced back to the reservoir at the surface through pipes 75 mm. in diameter. The rising main pipes have a diameter of 109 mm. The hydraulic pumping-engine forces 2"5 cubic metres of water per minute to the surface from 505 metres depth.

Hydraulic pumps are subject to shocks if proper care is not taken in the design. Low-pressure systems suffer more from shocks than high- pressure ones, because the weight of water employed is larger in propor- tion to the pressure. High-pressure systems witH weighted accumulators suffer more from shocks than those provided with steam or air accumu- lators, because of the inertia of the accumulator weight. A body of water at rest in a pipe exerts at any point a pressure proportional to the head or vertical height of the column above that point. Let

h = the head of water in ft. above any point, ^=the pressure in lbs. per sq. in. at that point then ^ = 0-43 A. HYDEAULIC TRANSMISSION OF POWER IN MINES. 1 93

A column of water in motion in a pipe has an acquired energy expressed in ft. -lbs. by

in wMcli W is the weight in lbs. and v the velocity in ft. per second.

If the velocity of a given weight of water is not altered, its acquired energy is not increased or diminished. But a column of water moving with an accelerating velocity exerts a less pressure than the same column at rest j and a column of water whose velocity is being retarded exerts a greater pressure than the same column at rest.

In high-pressure systems the energy due to velocity alone is small compared with the total energy, especially with steam or air accumulators. We have already described fully the system of hydraulic power trans- mission in mines and the application of the steam regulator or accumulator.

The foregoing figs. (167, 168, and 169) represent modern power plant recently designed by the author for a colliery.

In fig. 170 is illustrated the general construction of the duplex hydraulic pumps employed underground. In this particular instance the

working pressure at the surface is 1000 lbs. persq. in.

' The hydraulic pumps are placed in heavily watered dip ' workings

with 360 ft. lift to the sump at the bottom of the shaft, from which the

water is pumped to the surface by means of compound differential engines.

The shaft is 500 ft. deep, so that the vertical height from the hydraulic

pumps to the surface is 860 ft. Below the main hydraulic pumps are placed pilot hydraulic pumps for the purpose of following the coal workings

into the ' dip.'

13 — —

CHAPTER X.

ELECTRIC TKAHSMISSION OF POWER TO PUMPS.

Bbfoeb considering the merits of electric transmission, it should be remembered that all that is accomplished by the adoption of electricity is the transmission of the power of the steam engine, or other prime mover, to the working of the pump. It may take the place of a line of shafting or pump-rods, or it may enable the power to be transmitted over a great distance when other means of transmission would be impracti- cable or less eflBcient. Other systems of transmission have been applied, such as horizontal rods running on rollers, vertical rods on shafts, hydraulic transmission in pipes, and compressed air. At the Devon Great Consols the water power of the River Tamar was utilised for pumping by means of water-wheels actuating long lines of rods running on the surface on rollers, for distances of from half a mile to a mile. The rods then gave motion to the pumps in the shafts by means of angle-rods or quadrants changing the horizontal motion of the surface rod to the vertical motion of the pump-rods in the shafts. We do not know what was the mechanical efficiency of the plant, but it is evident that the loss of power with the horizontal rods must have been considerable. It is, however, questionable whether the work could have been done with greater efficiency by the application of electric

transmission. The losses were probably as follows :

Efficiency of water-wheel, say 70 per cent. ) Total mechanical efficiency,

,, ,, transmission, ,, 55 ,, i 38 per cent.

The losses on an electric system may be estimated thus :

Tnrbine efficiency, say 70 per cent.

Dynamo ,, i, 90 ,,

Line, 95 ,, Total mechanical efficiency, 38 per cent. Motor, 85

Gearing to work pumps, 75 ,,

In this particular instance gearing would have been necessary to convert the high speed of the electric motor into the low speed necessary —

ELECTRIC TRANSMISSION OF POWER TO PUMPS. 1 95

for working the shaft pumps ; but other systems of applying the electric motor have been brought into use. The newest system is that of pumping by means of high-lift centrifugal pumps actuated by means of electric motors, or working the pumps direct without pump-rods or gearing by means of slow-running electric motors. These systems involve the necessity of placing both the motors and pumps underground. The mechanical efficiencies of these two systems may be estimated thus : High-lift Centrifugal Pumps.—

Mechanical efficiency of the motive power steam engine, . 90 per cent.

dynamo, . 90 ,, ,, ,, ...

,, ,, line, . . . . . 95 ,,

motor, . . . . ,, ,, 85 ,,

,, ,, centrifugal pump, . .50 ,,

Total mechanical efficiency = 32'7 per cent. By substituting quick-running plunger pumps and slow-running electric motors for the centrifugal pump and quick-running motor, the efficiency of the pump, if not made to run at too high a speed, may be taken as 80 per cent. The total mechanical efficiency then becomes 52-3 per cent. The mechanical efficiency of the direct-acting mine pumping-engine, spear-rods, and plunger pump combined may be taken as 80 per cent. On the question of mechanical efficiency alone, the two electric systems preclude their adoption either for mining or other purposes. Waterworks pumping-engines and pumps combined have a mechanical efficiency of 85 per cent. With both types of engines last mentioned the efficiency is but little influenced by variations in speed within the limits of practical working. The electric systems have not that degree of constancy, especially with the centrifugal pump. This pump only gives its maximum efiSciency under critical conditions. A slight departure from such conditions causes the efficiency to fall off very rapidly. Under test this pump often gives 75 per cent, efficiency, but our experi- ence is that not more than 50 per cent, should be calculated on in practical work. Professor A. Eateau, in a paper read before the American Society of Mechanical Engineers, gave the mechanical efficiency of a number of turbo- centrifugal pumps at from 34 to 46 per cent. By the courtesy of Engineering, we are able to illustrate an electric high-lift centrifugal-pump system which has been applied for draining the Horcajo Mine in Spain. A section of the shaft showing the general arrangement of the motors and pumps is shown in fig. 171. There are four pumps each lifting against a mean head of 424 ft., or 1272 ft. in all; the bottom pump lifting to the one above, and so on to the top of the shaft. The lowest of three pumps, all quadruple centrifugals, is placed at a depth of 388 metres. It raises the water from the sump below to the second pump, which delivers the water still under pressure to the third 196 PUMPING MACHINERY.

pump, so that no air can enter into the hydraulic system. The whole bulk of water flows through all the pumps, which do the same duty at the same speed. Each of the pumps, therefore, has to overcome a mean head of 388/3=129-3

metres (about 424 ft.) ; but

it will be seen that the pumps are not at the same vertical distances apart, old galleries affording convenient spaces for the pump chambers. Thus the second pump receives the water with a pressure of 27'4

metres, and discharges it with 156'8 metres into the pipes; the pressures for the third pump are 14'1 and 143'4: metres, the latter being the final delivery pressure. The pumps are driven direct by means of electric motors on the pump spindles,

as shown in fig. 171. The mode of supporting the elec-

tric cables in the shaft is illus-

trated in fig. 174, whilst the general arrangement of the

power plant is indicated in

fig. 173. The power plant consists of compound steam- engines driving dynamos by means of belts. Sections of the pumps are

reproduced in fig. 172. The nickel-steel shaft bears four

wheels, /j, f^, /g, f^, of a diameter of 500 millimetres

(nearly 20 in.), arranged in pairs on both sides of the fixed

discs, ?j, l^. The discs are set Fio. 171. —Section of Shafts showing positions of with guide-blades on either High-lift Centrifugal Pumps at the Horcajo Mine, Spain. side. In the tests conducted ELECTRIC TRANSMISSION OF POWER TO PUMPS. 197 198 PUMPING MACHINERY. at the Winterthur works an efficiency of 76 per cent, was attained. In the mines pumps have, at 890 revolutions per minute, to raise 4'2 cubic metres

(925 gallons) of water per minute to a height of 130 metres (426"4 ft.). The disposition of the ports in the casting between the guide-blades and in

...J L-J Fig. 173.- -Plan of Power-house and Shaft, Horcajo Mine, Spain. the cover and casing of the pump can be seen in the diagrams. Connection with the suction pipe can be effected on the right or on the left, according

to the position of the pump in the chamber which the above-mentioned easy replacement of one pump by another necessitates. The shaft passes through the neck in a stuffing-bos, which is packed with ELECTRIC TRANSMISSION OP POWER TO PUMPS. 199 cotton, and then into a bearing wliich has been fitted with a ring lubricator. The second bearing in the pump cover is greased on the Stauffer system.

When the pump is in motion, axial forces arise in the wheel and the shaft, the thrust being directed from the cover towards the suction neck, and being taken up by the roller bearing. This roller bearing has to transmit a pressure of about 1 ton. The cook H, marked on fig. 172, and the elbow piping between the suction neck and the first pressure chamber are wanted only for the one pump, which is the lowermost at the time. There is a small ring channel about the shaft just aft the stuffing-box; the elbow piping just alluded to keeps this ring filled with water, lest air should be drawn into the pump.

The list of the pressure chambers next the cover is again fitted with two neck-pieces, through either of which conueotion can be established

Fig. 174. — Plan showing the mode of supporting tlie Electric Cables in the Shaft, Horcajo Mine.

with the hydraulic pipes. Cocks for fixing pressure gauges are provided in the second and fourth pressure chambers. The middle portion of the pump remains unobstructed for applying the hoisting tackle when the pump has to be taken to pieces. Three long screw-bolts having been removed, the cover and coupling pulley can be taken oiF, and the shaft with the fixed and loose parts of the pump can be pushed out half the shaft length. A ring is then screwed into the intermediate cover and the hoisting gear can be set in motion. The operation takes place every two or three months, and such a cleaning stops the pumping for five hours or less. The packing in the box is renewed on these occasions, as the high speed and the muddy water cause a rather rapid wear. Electrically-driven Plunger Pumps. —We illustrate in figs. 175 and 176

types of pumps and electric motors made in Germany. The Klein High-speed Pumps.—The Klein Company exhibited at —

200 PUMPING MACHINERY.

Diisseldorf, in the Mining Building, two high-speed electrically-driven pumps. One of these, a twin plunger pump, supplied the ornamental

fountain in the Exhibition grounds, and delivered 145,000 gallons per hour. The chief dimensions were : 1

ELECTRIC TRANSMISSION OF POWER TO PDMPS. 20

Diameter of plungers, 10-23 in.

Stroke, 15-74 ,, Speed, 150 revolutions per minute.

The pump was driven by belting by an electric motor of the Deutsche Elektricitats Werke, of Aachen, and ran at 400 revolutions, developing 200 horse-power.

The second pump, shown in fig. 175, was a double-acting high-speed

'^^^^^mi^W^mwMjfi

Fig. 176. —Electrically driven Plunger Pumps. mininfT pump. It was coupled direct to a 60 horse-power electric motor built by the Elektricitats Actien-Gesellschaft, Ernst H. Geist, of Gologne- Zollstock. It ran at a speed of 220 revolutions, and delivered 9900 gallons per hour against a head of 820 ft.

Diameter of plunger. 4-33 in. and 6-29 in. 7-87 in. Stroke, .

lubrication the The bearings were fitted with ring ; plunger was lubri- cated mechanically. It contained a small air-compressor for renewing the air in the delivery chamber, -vhich is constantly being absorbed by the water 202 PUMPING MACHINERY.

The suction valves were connected to the suction chamber by tubes, which lead the water vertically through the valve openings; by this means comparatively small quantities of water are accelerated and held in check at each stroke of the plunger, and an air-cushion is carried to the centre of the valve, preventing its upsetting. It will be seen that the Klein pump runs at 220 revolutions per minute, and that the motor is comparatively small in diameter. The speed of this type of pump has been reduced by making the motor larger, as illustrated in fig. 176, bringing down the number of revolutions per minute to 180; but a lower speed than that is desirable for efficiency and durability. CHAPTER XL

VALVE GEAKS OF PUMPING-ENGINES.

Almost all types of steam valves are used in pumping-engines, and the forms of valve gears are numerous.

The Cornish gear is illustrated in figs. 177 and 178. The Cornish engine is provided with what is known as ' equilibrium valves,' three in number—the admission, the equilibrium, and the exhaust—and each valve is actuated from a separate valve arbor or shaft. The admission or steam valve is closed by the cut-oflF tappet A, which is adjustable for different portions of the stroke. The valve is held closed by means of the catch B until it is released by the operation of the cataract rod C. The other valves are closed at the end of the stroke by tappets on another plug rod clearly shown in fig. 177, and are kept closed by catches.

On each gear arbor is a tappet arm shown in the details between figs. 177 and 178. The upper arbor actuates the steam valve, the middle one the equilibrium, and the lower arbor the exhaust valve; a handle is also provided on each arbor, that the valve may be commanded by hand in starting the engine. The plug rods which carry the tappets are clearly shown in fig. 177. The tappets are made of hard wood, faced with leather. During the steam or indoor stroke the long tappet A on the left hand plug rod closes the steam valve by striking the arm on the upper gear arbor. At the completion of this stroke the lower tappet on the right hand plug rod strikes the arm on the bottom arbor, and closes the exhaust and the injection valve. The cataract now releases a weight on the rod D of the middle or equilibrium arbor, and the weight falls, opening the equilibrium valve. The piston now being in equilibrium, makes its up stroke, towards the completion of which the upper tappet on the right hand plug rod strikes the arm on the middle arbor and closes the equilibrium valve. Steam is now cushioned above the piston, and the engine comes to rest, remaining in that condition till the cataract releases the top and bottom arbors, when the weights attached to them suddenly cause the opening of the steam, exhaust and injection v: Ives. 204 PUMPING MACHINERY.

By adjustments on the cataract rod C, the exhaust and injection valves are caused to open a little before the steam valve by releasing the lower

arbor a little before the top one. The steam valve tappet A is made long that it may close the steam valve early in the stroke.

To this tappet a long screw is attached, whereby it may be moved up

Fig. 177. Fig. 178.

Front Elevation. Side Elevation.

Figs. 177 and 178. —The Cornish Engine Valve Gear—an illustration of the engine is given on p. 89.

A, Expansion Tappet for closing the steam valve, adjustable for cutting off at from J to f the stroke. B, Catch for holding the valve closed, until released by the cataract rod C. D, D, D, Rods carrying weights for opening the valves when released by the cataracts A. and down on the plug rod to adjust the degree of expansion. Usually it is so adjusted that the cut-ofF takes place at about one-third of the stroke or a little later, but the steam is throttled up to the point of cut-off. The initial pressure is often considerably above the pressure at the point of cut-ofF, and the indicator diagrams often give a curve in which VALVE GEARS OF PUMPING- ENGINES. 205

the point of cut-off is not apparent ; the expansion curve after cut-off appear- ing to be part of a regular curve commencing with the initial pressure. This has given rise to misconception with casual observers. Cornish engines have been said to work with ten to fifteen expansions, judged from an imperfect inspection of the indicator diagrams. We have in another chapter discussed the principles which govern expansive working in the Cornish engines. As a matter of fact the highest rate of expansion obtained in the old or single Cornish engine is about four to one.

The cataract consists of a pump (fig. 179), placed in a tank so arranged

Fio. 179.—Cataract Gear of Cornish FlQ. 180. — Davey's Diflferential Valve Pumping-Engine. Gear. that when the engine makes its indoor or steam stroke the pump plunger side of the plug rod as shown. is lifted by the operation of a tappet on the The water taken in under the plunger on the up stroke is discharged back into the tank through an adjustable valve on the down stroke by means of the weight acting on the plunger. The adjustment of the discharge valve determines the speed at which the plunger descends, and thus regulates the time at which the cataract releases the catch on the valve arbor. This determines the time when the valve is opened. "With two cataracts there may be a pause at each end of the stroke. Generally only one cataract is used, and the engine only pauses at the completion of the equilibrium stroke. 206 PUMPING MACHINERY.

The Differential Valve Gear. —This gear dispenses with the tappet

o [^lEMO1

Fig. 181. —Davey's Differential Cut-off Motion and Trip Gear. motion of the Cornish gear, and introduces a governing element by which the valves are all closed or partially so when any erratic motion of the VALVE GEARS OF PUMPING-ENGINES. 207

2 208 PUMPING MACHINERY.

engine takes place owing to a loss of load. The general principle is that of causing the valves to be opened by means of a subsidiary steam cylinder at a fixed ratio of speed determined by the adjustment of a cataract. At the same time the engine by its motion tends to close the valves.

As long as the motion of opening is faster than that of closing, the

Fig. 183.—The Differential Gear as Fig. 184. —Cataract Gear worked by applied to cylindrical slide valve means of water pressure from the of compound engine. pumping main. valves remain open, but as soon as the engine motion becomes quicker than that of the cataract, then the valves begin to close.

Whilst the engine is working under normal conditions, then the opening and closing of the valves remains the same on each succeeding VALVE GEARS OF PUMPING-ENGINES. 209

stroke ; but when anything happens to cause the engine to race, then the valves close earlier.

The standard form of gear is shown in fig. 180. a and h are subsidiary steam cylinders, and c and d cataracts with adjusting plugs to enable the speed of the subsidiary pistons to be regulated.

To the main cataract rod e a lever/ is attached ; at the centre of this lever is a rod for giving motion to the engine valves through a rooking shaft H or other convenient means. To the outer end of the differential lever / is a rod attached by any convenient means to the engine so that it gets the motion of the engine piston on a reduced scale. The motion of the opposite ends of the p. S differential lever are in opposite direc- tions. The cataract d is for the pur- pose of determining the pause at the end of the stroke. It simply operates the steam valve of the main subsidiary cylinder by tappets on its piston rod, and in that way the time occupied in opening the valve of the steam cylinder a determines the pause between the strokes. It will be seen that in apply- ing this gear to engines with drop valves it is only necessary to have a rocking shaft between the gear and the valverods, with suitable connections to the valves. There are several additions to this gear, such as separate cut-off motion to the expansion valves, and a trip motion to cause a sudden closing of the valves in the case of breaking of the pump roils, etc. Both those motions are illustrated in fig. 181. The steam valve is opened by the gear through the curved lever d, and the cut-off takes place by the engine motion transmitted throngli the rod H. 14 2IO PUMPING MACHINERY,

The roller on the bent lever B forms an abutment on which the lever d is kept in position during the opening of the steam valve, but the engine motion produces an upward motion of the rod H, and removes the abut-

ment, causing the valve to drop. A trip motion is applied to the valve rod c.

Arranfienierit far allermq balance

Scale I to 3i

Fig. 186. —Shutter Valve on the back of main valve of low-pressure cylinder of non-rotative engine, for the purpose of enabling the engine to work out of balance when used in working sinking pumps.

The weight W keeps the bent lever A from releasing the trip /. The adjustment of the cataract G is such as to cause the weight W to be just raised, but not sufficient to release the trip/. Should the load suddenly

Fig. 187.—Meyer Cut-off Valves on the back of an ordinary D-slide valve. fall off the engine, then the rod H would move relatively faster than the cataract piston G, with the result that the weight W would be raised, releasing the trip /. VALVE GEARS OF PUMPING-ENGINES. 211

This trip gear is applied in a variety of ways—sometimes in compound engines to a valve between the cylinders, as in fig. 182. In this instance the weight W of the last illustration is substituted by the springs E E, the engine being double-acting, and the trip taking place on either stroke, closing a valve between the cylinders of the engine. Fig. 183 shows the gear applied to the working of cylindrical valves

with a definite cut-off' valve in the middle position. In this illustration

Fig. 188.

Fio. 189.

Figs. 188 and 189.—Corliss Gear.

the valves are those of a compound engine, having pistons moving in opposite directions.

Sometime.s the gear is worked by water taken from the pumping main,

as in fig. 184. In this case the subsidiary cylinders form cataracts in themselves, the regulation being effected by means of the water stop valves. Sometimes the differential action is produced withoutthe differential lever,

as in fig. 185, where the main valves A are actuated by the direct cataract motion and the cut-ofF valves B B by the engine motion. In this illustra- tion cushioning valves C C are shown on the high-pressure cylinder. 212 PUMPING MACHINERY.

Balancing Valve. —With double-acting mining engines working the double system of pump rods it is useful to be able to work the engine when it is out of balance, during sinking operations, or when one pump is

completely out of use, in the case of a breakdown of one pump, or from other causes. With the differential gear working drop valves, it is quite easy to work the engine under such conditions by throttling on the idle stroke, and in slide-valve engines a shutter valve has been applied, as in fig. 186. On the back of the low-pressure valve is placed a plate or shutter VALVE GEARS OF PUMPING- ENGINES. 213 carried with the valve and held in position by a screw and nut on the valve itself. This shutter is adjustable from the outside whilst the engine is running, and it is only necessaiy to draw the shutter over the port to throttle the steam on the side where the load is lightest. Eotative Engine Valve Gears. —Almost all kinds of valve gears in use on ordinary rotative engines may be applied to pumping-engines, but as pvunping-engines generally work slowly and have a constant load, auto- matic cut-ofF gears are not often required. Slide-valve engines have

Fig. 191. — Duplex Steam Pump Valve Motion. usually the Meyer cut-off valve on the back of the D-slide valve with a hand adjustment, as in fig. 187. Corliss valves are largely used, and are sometimes placed in the cylinder covers to reduce the clearance spaces, as in fig. 8, Chap. II. The ordinary Corliss gear is shown in figs. 188 and 189. An oscillating disc is placed on the side of the cylinder, and from this disc is taken the motion for the opening and closing of the exhaust valves and the opening of the steam valves. The opening of the steam valves is effected against the resistance of a spring, as shown in fig. 189, and the valve is released 214 PUMPING MACHINERY. by the opening of a trip or catch. On the release of the valve the spring closes it, and a dash pot introduced under the spring cushions the sudden motion. The release of the valve may be determined b^' the governor, as in fig.

Fio. 192. —Example of Valve Gear in which the steam valves are worked by cams, and the exhaust valves from a crank action. — Shown in cross section in

fig. 193.

188, or there may be a hand adjustment, which is generally sufficient in pumping-engines. Fig. 190 shows another form, the Corliss valves being arranged under the cylinder. Steam Pumps. —Steam pumps with steam-moved valves are numerous and varied. The steam piston is made to cause the main steam valve to be reversed at the end of the stroke by means of a tappet, or in other ways causing steam to press on a subsidiary piston connected with the main valve so as to reverse its position. VALVE GEARS OF PUMPING-ENGINES. 215

The tappet and lever are often dispensed with by arrangements of steam passages, covered and uncovered by the main piston, the main piston really performing the function of a subsidiary valve. Duplex Valve Gear. —The duplex steam pump consists of two steam pumps arranged side by side, the piston of one pump being made to give

Fig. 193. — Example of Valve Gear in which the steam valves are worked by cams, and the exhaust valves from a crank action. —Shown in longitudinal section

in fig. 192.

motion to the steam valve of the other. Its simplest form is given in fig. 191.

It will be seen that cushioning is necessary at the end of the stroke to prevent the pistons striliing the covers. That is effected by the double ports shown in the engraving.

Steam is admitted to the cylinder through the outer ports, whilst the exhaust takes place through the inner ones. The exhaust port is closed by the piston before the end of the stroke, and in that way the piston is prevented from striking the cover. 2l6 PUMPING MACHINEEY.

The device of making the working of one engine dependent on that of the other is old. Cornish engines in waterworks have been made to work alternately, when two engines were pumping into the same main, by coupling the valve gears of the engines by suitable connections, and as the steam stroke is made quicker than the water stroke, one water stroke commenced before the other was completed, thus keeping up a nearly constant flow in the mains. The author observed many years ago in using two independent steam pumps of precisely the same dimensions, and employing them to pump into the same rising main in a mining shaft, the rising main having no air vessel, that when the engines were working together they worked approxi- mately, as if their pistons had been coupled together by means of cranks at right angles. The reason was obvious. The pump plungers simply followed the line of least resistance.

In almost all non-rotative engines having the main steam valves worked by a subsidiary cylinder, it is quite easy to arrange a pair of engines side by side and so connect the valve gears that the duplex action may be

Fio. 194. —Example of Meyer Expansion Valves. Main and expansion valves worked from separate eccentrics. secured. By the duplex action we mean causing one piston to commence its stroke before the other finishes its stroke, and* that can be done by means of two engines, each capable of independent action. An example of such an arrangement is given in connection with a pair of engines in the chapter on Hydraulic Engines. Valve gears of pumping-engines are so varied that we can only indicate the general features of diiFerent valve motions. The method of applica- tion is quite simple when the motion is understood.

Cam Motion is applied to drop, piston, and Corliss valves. It may also be applied to ordinary slide valves. With cams, quick opening and closing of the valve with an interval of rest can be secured ; the valve has VALVE GEARS OF PUMPING-ENGINES. 217 therefore little useless motion. The valves most suitable for cam motion are those moved with little resistance.

Eccentric or Crank Motion. —This is the motion most commonly used. It is combined with a trip motion in the Corliss gear, and it is applied with modifications to actuating almost all kinds of valves. In figs. 192 and

193 there is a cam motion to the steam valve, and a crank motion to the exhaust. In fig. 194 we have eccentric motion to the main and expansion valves. It may here be observed that an eccentric is a crank with the crank pin larger than the shaft. Two eccentrics at right angles to each other on one shaft will drive another shaft if coupled to the driven shaft by connecting rods attached to cranks, the cranks of course being at right angles to one another.

NON-ROTATIVE ENGINES.

Fig. 195. —Method of working Inlet and Outlet Valves from the same Lever, so that the closing of one Valve is assured before the other opens. Used in Non-rotative Engines.

The inverted or marine type of triple-expansion engine has come largely into use for waterworks pumping engines. Such an engine is illustrated

in fig. 197 with the author's design of Corliss valve gear. It will be seen that the valves are placed in the cylinder covers, and are driven by means of a counter-shaft getting its motion by means of gearing from the engine shaft. There is a separate eccentric for each pair of steam and exhaust valves. The governor alters the time-release of the trip in the usual way,

but it is only applied to the admission valves of the high-pressure cylinder.

The time, if cut off for the other cylinders, is adjusted by hand. All the cut-ofF adjustments are held in position by a little counter-shaft indicated under the main counter-shaft shown in fig. 197, and the governor is so applied that in the event of the engine raciug it releases all the trip rods, 2l8 PUMPING MACHINERY. VALVE GEARS OF PUMPING-ENGINES. 219

3=

fio. 197.—Triple-expansiou Rotative Pumping-eugii,e with Corliss Valves. 220 PUMPING MACHINERY. so that all the admission valves remain closed, and the engine takes no steam in either of the cylinders till the attendant puts back the release into place. That is done whilst the engine is running by the single move- ment of a small lever. The gear will be readily understood from an

Steam-valve Motion. Exhaust-valve Motion.

^ u

Fig. 198.- -Details of Corliss Valve Motion of Engine

illustrated ft fig. 197.

mspection of the details in fig. 198. The exhaust-valve motion is such that the valve is not moved during the steam stroke, and therefore requires no lap more than that required for effective cover of the port. Wear and tear is thus reduced, as it is not moved under steam pressure except in the act of opening and closing.

CHAPTER XII.

WATEE-PEESSUEE PUMPING- ENGINES.

Watee-peessure engines are employed in pumping water, in winding materials from mines, and in driving machinery of various kinds.

For pumping water, the engine is usually applied direct to the pump, and in its simplest form is illustrated in fig. 199, which represents the water-pressure engine erected by Trevithick at the Druid Copper Mines, Illogan, near Redruth. The engine consisted of a 10-in. double-acting hydraulic cylinder A, provided with a piston having a stroke of 9 ft. From the cross-head of the engine, spear-rods descended to work the pumps. The valves consisted of two lead ' plugs,' or pistons, B and C. Rods attached to these plugs passed through stuffing-boxes in the valve- chest cover, and were connected by means of a chain passing over a chain-wheel D. A lever on the axis of the chain-wheel was connected to the tumbling weight W. The movement of the main piston towards the end of its stroke, acting by tappets fixed on the piston-rod, caused the tumbling weight to be pushed over the centre, as in fig. 200 ; and in that way the valves or plugs B and C were reversed, and the return stroke of the engine was effected.

If the plugs B and C were made to cover the ports, and thereby to prevent all slip of water past them, then the driving column would be absolutely stopped at the end of each stroke, as would be also the delivery column of the pumps, with consequent loss of energy. Severe shocks would also be produced at the end of each stroke. To reduce the severity of these shocks, Trevithick made the plugs B and C less deep than the width of the ports, as seen in fig. 199, and thereby allowed water to pass through from the driving column to the exhaust during the reversal of the stroke, thus preventing the absolute stoppage of the driving column. This device reduced the shock at the expense of water; and the efficiency of the engine must have been small. The loss of energy arising from fluctuations of velocity in the driving column is directly proportional to the weight of the driving column, and therefore to its length; consequently, when the height of the column 222 PUMPING MACHINERY. is mconsiderable compared with its length, and therefore its power small compared with its weiglit, the percentage of loss is very greatly increased. In applying hydraulic power for draining the dip and distant workings in mines, the author has practically experienced the difficulty of having to deal with a column very long compared with its height. A practical example is given in fig. 201, which represents two engines at Griff' Colliery, near Nuneaton : these are now employed to pump out a very long dip

Waier - IVessure fiunjjmif

Fig. 199. Jig. 200. piston valves D, cbain pulley Eeference Letters. —A, power cylinder ; B C, ; ; W, tumbling weight. working, and will be kept for draining it permanently. There are two hydraulic engines A and B, each capable of raising 150 gallons per minute to 150 ft. height, through 800 ft. of 1\-va.. delivery pipe CO, under an effective head in the driving column of 450 ft., this head being supplied through 1 900 ft. of 5-in. supply pipe D D. In commencing to get out the water from the dip, the first engine was placed as near as possible to the surface of the water. Suction pipes E were then added, as the WATER- PRESSURE PUMPING-ENGINES. 223

ifii I'

'I 'I

' I I i> I I

I I

a

ft.

.1 I

l^^^^^^^^^^^^j ^^^^^^^^^^^^^^^^ 2 24 PUMPING MACHINERY.

water was lowered, until a vertical depth of 25 ft. was reached; the second engine was then placed close down to the water-level, and the operation continued. In that way the pumping was uninterrupted, and a

distance of 150 ft. down the dip could be reached before it became

necessary to move either engine, the inclination of the dip being 1 in 6.

The water delivered at the top of the dip working is conducted to the sump S of the main pumping-engines, and the water for driving the

hydraulic engines is conveyed down the shaft from the surface of the

mine ; so that the main pumping-engines have to pump the water delivered at the sump, which includes the water used in working the

hydraulic engines. The exhaust water from the power cylinder is delivered direct into the rising main of the hydraulic pump, so that the hydraulic engines work with an effective head equal to the height of the supply cistern above the main engine sump S.

A longitudinal section of the hydraulic engines is given in fig. 202. The stroke is 2 ft. 6 in., diameter of power cylinder 6J in., of pump 8f in. /8'75\^ 150 Thus the useful effect is represented by ( ^-^) x —- = 65 per cent. The speed of working is twelve double strokes per minute. It will be seen that the pump is provided with a loose liner M ; by withdrawing this liner, and putting in a larger piston of 12| in. diameter, the capacity of the pump is doubled, enabling the engine to pump double the quantity to half the height. The larger piston is used until half the total depth is reached, when it becomes necessary to insert the liner, and use the smaller piston for the remaining depth. The valves of the power cylinder are of a very peculiar construction, and were designed by the author with a view to get rid of the difiiculties encountered in applying slides, and other ordinary valves, to water- pressure engines. They are shown to a larger scale in figs. 203 and 204.

Keferring to fig. 203, the top orifice F is the inlet, and the bottom one G the outlet or eduction pipe; and the pipes J and K form communica- tions to the two ends of the power cylinder. The eduction valves are annular gun-metal pistons H H, working vertically, and each having two valve-beats, one on the inner edge I and one on the outer edge of its bottom face. As the annular valve descends, the outside beat closes the communication to the eduction pipe ; and the inl^^ valve L, rising against the inner beat, closes the supply. This inlet valve is an ordinary single- beat mushroom valve, with its stalk projecting upwards and attached at the top to a piston N ; the bottom face of this piston is constantly under the pressure of the driving column, while the top face is exposed alternately to the pressure of the driving column and to the pressure in the eduction pipe by means of a small gun-metal slide-valve P (fig. 204), actuated by a lever Q and tappet-rod E (fig. 202). The action of the two valves in combination will be readily seen by supposing that the exhaust valve is closed and the pressure valve is open, as on the left- WATER-PRESSURE PUMPING-ENGINES. 225

IS 2 26 PUMPING MACHINERY.

hand side of fig. 203 ; then the pressure valve L, in closing, rises up against the annular exhaust valve H, and lifts it, opening the exhaust orifice G. The valves are now in the position shown on the right-hand side of fig. 183. Towards the end of the stroke, an arm S attached to the cross-head of the engine strikes the tappet and so pushes the slide- valve over, into such a position that the top of the right-hand valve-piston is exposed to the pressure column and that of the other to the eduction column. The main valves are thereby reversed : the right-hand piston being vmder equal pressure top and bottom, the pressure on the top of the annular valve H forces it downwards, carrying the pressure valve L

with it. When the valve H has come down on its beat 0, closing the exhaust orifice, the valve L continues to descend under the pressure

above it, and opens the pipe K to the pressure water, as on the left-hand

side of fig. 203. On the other side the ascending piston causes its inlet valve to close, and its eduction valve to open. With this successive and alternate action of the valves they cannot in working be placed in a

position which would allow any water to slip through uselessly; that is to say, it is impossible for the exhaust valve and the pressure valve ever to be both of them open at the same time. The opening of the exhaust valve depends on the closing of the pressure valve, and the pressure valve

cannot open until after the exhaust valve has closed, so that it is

impossible for either valve to be open except while the other valve is closed. The double-acting engines just described were specially designed for the purpose they are applied to, which necessitated their occupying a very small space, and being very portable. But in the majority of cases, especially where the engines are applied under considerable pressure, and where the water is at all dirty, the author uses plungers instead of pistons. An example of a pair of engines with plungers, and applied under very heavy pressure, is given in fig. 205. These engines were made for pumping brine of 1-3 specific gravity. Each hydraulic engine is capable of raising per minute 66 gallons of

brine 1000 ft. high, with an effective pressure of 560 lbs. per sq. in. in the accumulator A, equivalent to 1000 ft. head of brine. In the larger view (fig. 206), B B are the power plungers of 8-in. diameter, reduced to 5|-in. diameter in the pumping cylindqjs C C. The rising and falling columns of the power water balance each other, and the head of the accumulator pressure exactly balances that of the brine in the rising main, so that the useful effect is simply given by the ratio between the total area of the plunger at B and the reduced annular area at C. g2 _ C5-125')2 Hence useful effect = ^ i-=59 per cent. The power valves DD are precisely similar to those already described, but are placed in separate boxes, because the power cylinders are separated; they are shown in section to a larger scale in fig. 207, and one of the pump valves E E in WATER-PRESSURE PTJMPING-ENGINES. 227

at- 2^ansIielcL SaZt Mirve^

Engine Valve-s.

FiQ. 207.

I

i i

I ScaU VJZ ^

Fig. 208. I % I Fm. 205. VA'////////////////////^^^^^^ I

Fios. 206, 207, and 208. 228 PUMPING MACHINERY. WATER-PRESSURE PUMPING-ENGINES. 229 fig. 208. The change valve G (fig. 206) ia worked by a tappet arrange- ment similar to that already described for the dip-engines. The effect of fluctuations of velocity in the driving column from an accumulator is similar to that in a column with a natural head; and the effect of enlarging the ram of the accumulator is to reduce the velocity of the moving weight, in the same way as the velocity of the water is reduced by enlarging the pipe in the other case. Hence it is highly important that when an accumulator is used it should be very large, thereby making its pulsations very slow. As an example of the practical application of water-pressure machinery to the working of a metalliferous mine in a hilly district, the author has prepared figs. 209 to 215, which represent the machinery designed by him for the A. D. Lead Mine, near Eichmond, Yorkshire.

It will be seen from fig. 209 that there is a reservoir situated on the hillside above the mine, at an elevation of about 500 ft. above the adit level. Pipes are led from this reservoir down the hillside for a distance of 1800 ft., and are then taken 240 ft. down a vertical shaft to the interior of the mine, at the inner end of the adit level. At this point a large chamber is excavated, to contain the pumping and winding engines.

The pumping-engine (figs. 210, 211, and 212) consists of two vertical hydraulic cylinders A A, each having a power ram 12 in. in diameter with a

7-ft. stroke. The rams are connected together by a chain passing over an overhead chain-pulley P (fig. 211), so that one ram makes its up stroke whilst the other is descending. A rod 3 in. in diameter, fixed to the ram, passes down through a stuffing-box in the bottom of the hydraulic cylinder, and is attached to the pump-rod. The pumps are each 13 in. in diameter, and of course have the same stroke as the hydraulic rams. On each hydraulic cylinder is placed a valve-box B, shown in section in fig. 212, with valves similar to those already described in connection with the other

hydraulic engines ; both valve-boxes are connected with a single change- valve C. The pumps (fig. 210) are of the ordinary bucket type, provided with clack pieces, door pieces, and wind bores, such as are generally used for sinking purposes. The pumps will be used in deepening the shaft, and the hydraulic engines are proportioned for raising, at 6J strokes per minute, 500 gallons of water from a depth of 360 ft. to the adit level, the depth being about 120 ft. At the full depth, with 534 ft. 13^ 360 rams, the useful efi'ect will be represented by ^ = head on the .j-;^^—02 RqI i.^ — O 004: 84 per cent. The winding-engine (figs. 213 and 214) consists of a pair of double- acting hydraulic cylinders, coupled to right-angled cranks on the driving shaft, which latter is geared to the winding drum by a spur pinion, the general arrangement of the engine being very similar to that of a steam winding-engine. The gearing has a proportion of 1 to 6, and the winding drum is 6 ft. in diameter. The weight to be raised is 2 tons of ore at a 230 PUMPING MACHINERY.

ScoJa'/Wi/'mM RuTtp

Scale

««

-^ ^ Foot VaZve^

^53* Feet- WATER-PRESSURE PUMPING-ENGINES. 231 time. The cylinders are 5^ in. in diameter, have a 16-in. stroke, and run at 19^ rev. per minute, giving a speed of 60 ft. per minute to the

rope. The admission and eduction valves are somewhat similar in con- struction to those already described, but are driven by means of eccentrics, having a link-reversing motion, and are put in equilibrium by the some- 232 JUMPING MACHINERY.

Piunjiirtff Enaine> at A D Mine-

Fio. 212. WATER-PRESSURE PUMPING-ENGINES. 233

Windirvg Erv^x^ a^ A D Miru^-

Side' EUvcOiorv. Scale ^/^S^

Fig. 213

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Planf

Fig. 214.

LotxffihicUn.o.J- S^cbiorv of Cyliix.(Ler cut J. VaZi'C

Fig. 215. '^ .(i!e. W 2 34 PDMPING MACHINERY.

what novel arrangement shown in fig. 215. The two mushroom admission valves E E are on the same spindle, on which are also fixed two pistons

G G, each equal in diameter to the annular eduction valves J J. These pistons work in cylinders K K, placed beyond the engine ports, and form- ing continuations of the valve-boi. By following out the motion of the

valves, as given by the eccentric, it will be seen that the eccentric has

only to overcome the resistance due to friction, because in all positions the valves are balanced as regards pressures. This the author considers

an important improvement in this type of hydraulic valve, as it enables very large valves to be used, and thus prevents any loss from throttling. It also enables the reversing to be done by means of a link motion, and gives easy and complete control over the engine. Having described some examples of water-pressure engines of general application, the author proceeds to describe two engines specially designed for particular cases.

In fig. 216 is shown a peculiar application of a hydraulic pumping- eugine, and one which the author has had occasion to adopt in several instances for mining operations. At the Hutton Henry Colliery, near Wingate, Durham, a certain quantity of water comes out of the strata at

an intermediate point A, in a shaft where it is not convenient to place a pump except at the bottom. The water issuing at A has therefore to be

taken down to the bottom before being forced to the surface. It is taken down from the point A in a down suction-pipe C C to the hydraulic pump

B, and is delivered through the delivery pipe D D to the surface ; so that

the work done by the pump is that due to the difference between 866 ft. head in the delivery pipe and 502 ft. in the down suction-pipe, or to 364 ft. only. The power cylinder, 6J in. in diameter, with a 1 ft. 3 in. stroke, is actuated by means of a driving column from the point E, having an effective pressure of 260 ft. head. The power cylhider and pump, fig. 217, are both single-acting ; but the pump is a piston pump of a peculiar construction. The pressure of the down suction column is constantly in the annular space between the piston-rod. If in. in diameter, and the inside of the pump barrel, 4 in. in diameter. During the forward or delivery stroke of the pump, the pressure behind the annular area of the pump piston assists the plunger of the power cylinder ; and the return stroke is produced entirely by the pressure from the down suction column beinf; brought to bear on the full front area of the pump piston, the effective pressure for the return stroke being therefore that due to the difierence between the full front area of the pump piston and the annular area of its back face, or, in other words, / 4 \2 3g4 to the area of the piston-rod. The useful effect is ^r^r^— I x r-—• = 60 (\D'12o/ 260 per cent. The engine is designed to work at 10^ double strokes, and to raise 7 gallons per minute. It should be added that the driving water is water which would run down to the bottom of this shaft in any case, and is simply utilised for pumping. WATER-PRESSURE PUMPING-ENGINES. 235

Fio. 216, Mode' of deahng H'ilh Water convina vtvto Shxiuft,

HnUciv- Henry CoTU^ery, WvrhgaZey

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GeixerdL Arrarvqemen^.

Engine'

Li on^iluydinaZ' SecVwrv of Pu,mpvi%q Enavrve-

Power Cylinder J\unxp

Fig. 217.

Figs, 216 and 217. 236 PUMPING MACHINERY.

I WATER-PRESSURE PTTMPING-ENGINES. 237

In figs. 218 and 219 is shown a pumping-engine designed by the author to work under a most peculiar condition, namely that of making a single pipe serve both for the driving column of the engine and as the delivery pipe of the pump. A is the vertical pump plunger, and B B a pair of power plungers, all three coupled side by side to the same cross-head C. D is the suction valve of the pump, and E the delivery valve. F is the pipe which serves both for the delivery from the pump and for the supply to the power cylinder. It is in connection with the power cylinders at G, and has a branch H connected to the delivery valve-box above the delivery valve E. The cross-head C is of sufficient weight to cause the descent of the three plungers against the head of water in the pipe F. Water has to be pumped from the point K to the point M. The power water is obtained from the column L. J is a single-acting valve-box, similar to those already described in connection with the other hydraulic engines, and has a change valve actuated through a tappet-rod and wire by the rise and fall of the plungers. The modus operandi iaa,j be thus described. During the up stroke the plungers B B are being raised by means of the pressure in the driving column L, and water is being drawn up into the pump cylinder A through the suction valve D. On the completion of the up stroke, the change valve in the valve-box J is reversed by the tappe1>rod and wire, and the other valves are also reversed by the water itself, so that the communication to the plungers B B from the driving column L is closed, and also the suction valve D belonging to the lower sump K ; while the delivery pipe to the upper sump M is opened. The weight of the cross-head C then causes the plungers to descend, forcing the water out of the pump and the power cylinders, through the pipe F, up into the sump M ; and the operation is repeated in the same way. It will thus be seen that the pipe F serves as a supply pipe to the engine during the up stroke, and as a delivery pipe from the pump during the return stroke. This engine is specially applicable to the draining of dip workings, but can only be used to advantage in fixed positions, since it is not so portable as the other dip-working engines already described.

If a pump situated at J be substituted for the driving column L (fig. 218) the valve-box J can be done away with, and the pipe F connected directly to the pump barrel. The dip-engine would then derive its motion from this pump, and would work simultaneously with it.

The two engines last described are of very limited application ; but they present several points of interest, particularly as, in the application of water power, engineers are oftea called upon to devise special means in order to meet special contingencies. The question of applying hydraulic power economically by means of rotative engines to varying resistances has received considerable attention. A very clever and ingenious device —that of automatically altering the stroke by means of a resistance governor—has been used. There are other methods which readily suggest themselves, such as levers having shifting ;

238 PUMPING MACHINERY.

fulcrums, and similar devices ; but the author has never found any such mechanism sufficiently practical for general application. The dip engine already described (fig. 202) might be provided with a lever having a shifting fulcrum, between the power-cylinder and the pump but the economy so gained, beyond that effected by the loose liner and change of piston, would not compensate for the extra complication. In rotative engines having fly-wheels the admission valves of the power cylinders may be made to close at varying points in the stroke, by means of known mechanisms ; and if the ends of the cylinders are provided with vacuum valves opening inwards, from pipes dipping into a waste-water cistern, the speed of the engine may be kept constant, whilst the supply of pressure water is varied to meet the varying resistances to which the engine may be applied. The cylinder would be partly filled from the pressure pipe, and then the remaining space would be automatically filled from the waste tank. By the use of three double-acting cylinders working on one crank-shaft, the portion of the stroke during which the pressure water would be admitted might be considerably varied, without causing a great fluctuation in the velocity of the driving column.

The foregoing is from a paper by the author in the Proceedings of the Institution of Mechanical Engineers. Inertia of Water Column and Pump Rods.—In applying water- pressure engines to the working of mining pumps through the medium of pump rods, the author met with the difficulty arising from the inertia of the pump rods and attachments in addition to the inertia of the motive power column. The effect of inertia of pump rods has been dealt with in Chap. IV. Assuming that by the use of an air vessel, or by other means, the water pressure may be preserved nearly constant at the engine, how is

the inertia of the pump rods to be compensated for 1 Fig. 220 represents the application of a water-pressure engine to the working of mine pumps by means of the quadrants g g' and the rods h li. Assuming the rods to possess considerable weight, then a pressure above that required by the resistance of the pumps is necessary at the beginning, and a less pressure towards the end of the stroke.

This engine is employed to actuate pumps having heavy reciprocating parts, such as well or shaft pumps actuated by means of pump rods. a and h are motive power cylinders provided with admission and exhaust

valves ; c is a plunger or piston connected to the pump by means of the

rod d, connecting rods e and /, quadrants g and g, and pump rods h and

h'. The said plunger or piston is connected directly or indirectly by means

of a rod i to the piston or plunger j, working in a water cylinder k, having

1 ; 1 are partly filled at the ends air vessels 1 these air vessels 1 with water, so that when the piston or plunger j is moved in one direction or the other, the air above the water in one of the air vessels is compressed, whilst the air in the other is rarefied. In this way when the piston or plunger is moving from one end of its WATER- PRESSURE PUMPING-ENaiNES. 239

v^^\i>^i.'i\'^'^'^'ui\ifi -^^^^^^^ ^m

Cr^-(ThK'.Wfi\

''- :W-lTV-i rA--«f! n

'ti-

uixzi.'i.'Vl|

a

c iiHilii C \& 240 PUMPING MACHINERY.

stroke, it is assisted by the pressure of the air compressed in the air vessel at that end, and in moving from mid position towards the other end its motion is retarded by the compression of the air in the air vessel at the end towards which the piston is moving. Thus the motion of the motive power piston or plunger c is assisted at the beginning and resisted towards the end of the stroke, in this way compensating for the inertia of the pump

Fig. 222. —Du]Iex Hydraulic Pumps. rods and connections, and the inertia of the water xolumn actuating the motive power piston or plunger c. To minimise the loss of energy arising from shock in the motive power water column caused by the fluctuations in velocity of the column, the author devised the apparatus shown in fig. 221. p is the motive power water pipe, q a plunger or piston working in a cylinder r, connected to the pipe p. Attached to the plunger g' is a piston or plunger s working in a cylinder t ; from the cylinder t passes a pipe u connected to the air vessel

V, partly filled with water. j« is a plunger attached to the piston s, and working in the pump cylinder x, y y are suction and dehvery valves in the

WATER-PRESSTJRE PUMPING-ENGINES. 241

chamber ?.. Any leakage past the pistoa s passes into the cylinder x, and on the descent of the plunger w, the air and water present is forced out and into the air vessel v, so that the latter is by this means kept charged.

The areas of the pistons q and s respectively are so proportioned, and the pressure of the air in the air vessel v is so regulated that the pistons or plungers shall be towards the bottom of their strokes when the pressure in the motive power pipe is normal or below the normal, and the water in the pipe p is in motion. Should the motion of the water in the pipe p be suddenly stopped, then the increased pressure in the pipe p, due to the inertia of the water, would push up the pistons or plungers q and s, and

FiQ. 223. —Power Cylinder and Valves of duplex hydraulic pump. thus force the water above the piston s into the air vessel v, thereby compressing the air. The energy thus stored in the air vessel would be given out again to the water in the pipe p by the return of the plunger when the pressure in the pipe p fell below the normal pressure. A loaded relief valve of any suitable form is placed at 2', to prevent any excess of pressure in the air vessel v. We have already described very fully the principles and construction of water-pressure engines. Fig. 222 illustrates a pair of low-pressure engines employed to pump water to a higher elevation than the source of power. Water flowing from one reservoir to another at a lower level is made to pump water to supply a district above the higher reservoir. The engines are arranged to work on the duplex plan, but can easily be altered to enable them to be worked singly.

The hydraulic piston D (fig. 223) is cushioned by causing it to enter a recess at each end of the cylinder, and so confine the water being exhausted. 16 242 PUMPING MACHINERY.

The power valves C (fig. 223) are of the piston type, with a subsidiary- valve A and subsidiary piston B, by means of which they are, actuated. The duplex action is secured by means of connecting pipes between the subsidiary valve of one engine and the subsidiary cylinder of the other. To enable the engines to work separately it is only necessary to connect the pipes from the subsidiary valve box of each engine to its own subsidiary cylinder. rL.iTi-: ,v,] \T<, f,i,-r pa^y -Hi

t wiiiiiMiiiid riiiM]iiii^^ lMit;iiir, r.il iniliL^liaiii ^^'atrl wdi l;s.

CHAPTER XIII.

WATEEWOKKS ENGINES.

Town Water Supply. — Machinery for this purpose is very varied in character and design, partly owing to the varied nature of the application and partly owing to the changes which have taken place arising from the introduction of high-pressure steam and the progress which has been made in design, in the simplification of parts, and in improved details. With the older form of engine, the house and engine were combined into one

structure, as is the case with beam engines generally.

The modern engine is self-contained and only requires a house as shelter. Pumping from wells requires a special design of engine and pump to suit the local circumstances. It may be advisable to use the permanent

engine to drain the well during sinking operations, or it may be advisable to use bore-holes as wells. It may be necessary to pump the water raised from the well into an elevated reservoir or into the distributing mains by

the same engine ; or it may be better to have a separate engine. These are questions infliuenced by local circumstances.

Water supply from wells is, generally speaking, obtained from a depth

not exceeding 200 or 300 ft. At that depth pumping is not so expensive as to become of great import- ance, but as the expense of fuel, upkeep and some of the working charges increase somewhat in the proportion to the increase in depth from which

the water is pumped, it is worth while to expend considerable capital in order to obviate having to pump water from excessive depths. When water supply is taken from rivers it often becomes necessary to have

pumps to lift the unfiltered water to filter beds, and others to pump this filtered water into the distributing mains. The two sets of pumps are sometimes actuated from the same engine, but the more modem and

approved plan is to have a separate engine for each purpose. The filter pumps are generally of small power and large capacity. The simplest forms are the centrifugal and the ordinary steam pump, but both are large steam consumers. Such pumps are, however, simple, and occupy but little space. The author has used the ordinary non-condensing steam 244 PUMPING MACHINERY. pump for the purpose of pumping water to filters on a plan which secures economy. The system is illustrated in fig. 12, Chap. II., and described on p. 46. A separate boiler having a working pressure of 30 or 40 lbs. per sq. in. above that of the boilers of the main engines may be used for the filter pumps, and the filter pump engines may be made to exhaust into the boilers of the main engines. In this way a simple single-cylinder non-condensing steam pump may be made use of without the very great waste of steam usually resulting from the use of such pumps. Water-pressure engines taking their power from the water mains may under certain circumstances, be also used for the purpose.

Where the lift is only a few feet, a very convenient method is the use of

' a centrifugal pump with a Pelton ' wheel fixed on the same spindle (fig. 255, Chap. XV.), the Pelton wheel being driven by means of water taken from the mains.

Generally speaking, the filter pumps require more power than it would be advisable to apply by the methods just named. Assuming that the main engines are required to be of 300 H.P. with a lift of 200 ft., then the filter pumps would be required to be considerably over 30 H.P. for a lift of

20 ft. Engines are sometimes used to pump from a water main at one pressure into another at a higher pressure. In Birmingham the distribution is divided into four zones with a diflference in level between the one zone and the next of from 100 ft. to 200 ft. Two compound pumping-engines each of two million gallons per day capacity are used to pump water from the low-level zone main into the mid-level zone main, the pressures being

110 ft. in the low-level and 250 ft. in the mid-level main. Water-pressure pumps are sometimes used for water supply, and where a natural head of water is available the economy is obvious. Such pumps have also been used with the power derived from water falling from one reservoir level to another, to pump a supply to a district above the higher reservoir. The water-pressure pump is a simple machine requiring little attention, and when a counter is attached it becomes a fairly good water meter. Sometimes waterworks engines are employed to pump direct into the distributing mains without the use of a reservoir for the purpose of main- taining a constant pressure, the pressure being rftaintained during the fluctuations in demand by alterations in the speed of the engines. Balanced valves have also been used to maintain a constant pressure against the pump.

With waterworks plant reserve power is necessary, and that reserve must be based on the maximum supply which takes place either in dry summer or severe winter. The capacity of each engine must also be above the maximum require- ments to allow for reduced delivery of the pump when out of order. In addition to reserve engines, each engine should have a reserve WATERWORKS ENGINES. 245

capacity of say 30 per cent. The question as to what reserve power engines should have depends on the extent of the water supply. With small supplies the unit of power becomes small, and 100 per cent, reserve power is necessary to avoid having very small units. In large establishments, where the units of power become numerous, then 33 per cent, may suffice, say one spare engine in three. A town having a mean supply of 20,000,000 gallons per day might make a demand on the pumping machinery to the extent of 28,000,000 or 30,000,000 gallons per day during a dry summer or a severe frost. The following diagram (fig. 224) shows the fluctuation in water supply in the city of Birmingham for the years 1896-7. Where engines pump direct into the distributing mains without a service reservoir, the reserve power of the engines must be increased, because the variation in demand during twenty-four hours largely exceeds the mean supply. Service reservoirs should contain at least twenty-four hours' supply.

It is not desirable to pump into distributing mains without connection to a service reservoir, although sometimes it becomes necessary. Types of Waterworks Engines. —The single cylinder Cornish engine (fig. 225) was formerly the most favoured, and very justly so, because, with the pressure of steam then available—30 to 40 lbs. —it was the most economical engine made.

Under proper conditions, large engines required only 24 to 26 lbs. of steam per pamp H.P., a performance which was only equalled by compound rotative Woolf engines working with much higher boiler pressure. The

Cornish engine in the single cylinder form is only suited to low pressures, and for that reason it has given place to compound engines of the double or triple class.

The general form of compound rotative beam engines is shown in figs. 226 and 227. A double-acting pump is actuated from the crank end of the beam, as in fig. 226, or two single-acting pumps are placed one on each side of the beam centre, as in fig. 227. This type of engine was generally worked with the Woolf distribution of steam—that is, with a cut-off valve on the high-pressure cylinder only. To work such engines on the receiver plan with a cut-ofF on each cylinder a very heavy fly-wheel is required ; but if two engines are com- bined to form a compound engine coupled to the same shaft with cranks at right angles, then a lighter fly-wheel suffices. Since it has become practicable to make boilers which are durable and safe, carrying very high pressures, new types of pumping-engines are taking the place of the old beam engines. It had long been recognised that there was a distinct advantage in making the engine what is termed ' direct acting ' —that is, in attaching the 246 PUMPING MACHINERY.

Toi-dL Daftly Ave^ro-^es for l-he. Ye

of Gallons t^ MMion^— ,„ 9 WATERWORKS ENGINES. 247 pump direct to the piston rod instead of by an indirect connection through a beam and connecting rod. When higher boiler pressures became usual,

Fig. 225. —Cornish Pumping- Engine —Wolverhampton Watenvorks.

Diameter of cylinder, Height of lift, . . . .200 ft. Valve gear—Davey's differential.

Surface condenser, 380 sq. ft. of surface. Duty = 63 millions on an evaporation of

8 lbs. of water per 1 lb. of coal. 248 PUMPING MACHINERY.

Duty Trial of Engine illustrated on page 251, by Professor W. Cawthorne Unwin, F.K.S.

The Engine. —The engine is a triple-expansion, vertical, three-crank fly- wheel engine. It has a surface condenser, the circulating water in which

Fig. 226. —Compound Beam Engine—London Waterworks.

engine. The crank sequence is intermediate, is the water pumped by the the cylinders are Corliss valves high, low pressure. The steam valves on WATERWORKS ENGINES. 249 in the cylinder heads, with a very simple and satisfactory trip gear. The cylinder clearances, as shown in the table below, are exceptionally small.

The trip gear of the high-pressure cylinder is controlled by a speed governor. The trip gears of the other cylinders are ordinarily set to a fixed cut-ofF, but this is variable by hand adjustment. According to the scales marked on the gear, the cut-oflf was at 0'26 in the low-pressure cylinder.

Fig. 227. —Leicester Sewage Works Compound Beam Pumping-Engine. High-pressure cylinder, 30 in. diameter x 5 ft. 9J in. stroke.

Low-pressure cylinder, 48 in. diameter x 8 ft. 6 in. stroke.

Boiler pressure, 80 lbs. Pumps, piston and plunger type, piston 27J in. diameter x 5 ft. 9^ in. stroke. Fly-wheel, 21 ft. diameter, weight 21 tons. Revolutions per minute, 12.

Feed water per L H. P. per hour reported to be 15 '4 lbs. to 18 '3 lbs. Indicated horse power, 200.

at 0'28 in the intermediate-pressure cylinder, and at about 0'28 in the high-pressure cylinder. The steam cylinders are steam jacketed—the high- pressure and intermediate-pressure with boiler steam, and the low-pressure with steam of about 50 lbs. pressure per square inch. There are jacketed receivers between the intermediate-pressure and low-pressure cylinders. The drainage from the jackets is ordinarily led direct to the boilers. In 2 50 PUMPING MACHINERY. this trial it was cut off from the boilers to be measured and discharged to waste. The other engine in the house was during this trial blanked off. Each engine has three single-acting ram pumps, with numerous metal valves of small diameter faced with rubber. The pump discharge is therefore very uniform.

wrip'

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Fiu. 228. — Triple-expansion Pumping-Engine—City of Leeds Waterworks.

Cylinders, 15 in. , 24 and 40 in. diameter "i

Plunger pumps, 13J in. diameter ) To raise 1860 gallons per minute against a head of 300 ft. Boiler pressure, 150 lbs.

There are two Lancashire boilers with cross tubes in the flues, and

fitted with Bennis's sprinkling stokers. Only one boiler was used, the feed-heaters an other being blanked ofl^. There are also and economiser. WATERWORKS ENGINES. 251

FlO. 229. —Triple-expansion Pumping- Engine—City of Leeds Waterworks. ,

252 PUMPING MACHINERY.

The coal used in this trial was Welsh Powell Duffryn steam coal. It had, however, to be broken rather small before being placed in the hoppers of the Bennis stokers, and as it does not cake on the grate, some fell through unburned. It is doubtful if hard coal of this description is well adapted for use with automatic sprinkling stokers.

Dimensions of Engine and Boilek. Boiler— 28 ft. length by 7 ft. Boiler, / ...... 6 in. diam. Flues, 3 ft. diameter, tapered to 2 ft. 6 in. at the back end, with four cross tubes.

Grate area, . . sq. ft. ... . 36 Total heating surface, ..... 850 sq. ft. Green's eoonomiser, 128 tubes, having a heating surface of 1280 sq. ft.

Engine— Diameter of cylinders, .... 15in., 25 in., and 40iR One piston-rod to each cylinder, 3 1 in. diam. Effective piston area, high-pressure, top, 176-7 sq. in. bottom, 165-66 sq. in. , intermediate-pressure, top, 490-9 sq. in.

,, bottom, 479-86 sq. in. low-pressure, top, 1256-6 sq. in.

,, bottom 1245-56 sq. in. Stroke, high-pressure, 36-00 in.

, 35-97 in. , intermediate-pressure,

, , low-pressure, 35-99 in. Diameter of pump rams, 13-482 in. Mean area, 142-74 sq. in.

Mean stroke, . 2-999 ft.

Mean ratio of steam cylinders, 1 : 2-84: 7-33 Volume described by pistons per stroke, high-pressure 3-78 cubic ft. Volume described by pistons per stroke, intermediate pressure 10-40 cubic ft. Volume described by pistons per stroke, low-pressure. 26 -62 cubic ft. Mean clearance volume, high-pressure, -0897 cubic ft.

,, ,, inteimediate-pressure, 0-179 cubic ft.

,, ,, low-pressure. 0-44 cubic ft. Percentage of clearance to cylinder volume, high- pressure, 2-38 Percentage of clearance to cylinder volume, intermediate- pressure, ...... 1-72 Percentage of clearance to cylinder volume, low-pressure, 1-65

Capacity of high-pressure receiver, . 16-3 cubic ft. 20-0 ,, intermediate-pressure receiver, . cubic ft.

Measuring Ai-rangements. —A counter and set of gauges were attached to the engine. The two most important gauges for the purpose of the trial, the suction and delivery gauges on the pun^ mains, were sent to Messrs Schaifer & Budenberg after the trial, and they were found to be correct. For measuring the condensed steam from the surface condenser two tanks were provided, each placed on a weighing machine. A pipe with a two-way cock delivered the condensed steam or air-pump discharge into these alternately into each for half an hour. The weight of the tanks themselves had been balanced by lead attached permanently to the weighing machines. Hence the weight found in the tank, which had been filling during each half-hour, was the net weight of steam used by the engine in the half-hour. 7'., /•«.. /-«./. L':'i2. Vl.ATK AV. 1 1

'I'l ij'L-t'x|';iii>ii'ii I'lniipin^ Engine, i'it\ nf Lcnis Watorwrjrk^,

WATERWORKS ENGINES. 253

While one tank received the condensed steam the other was emptied. The

weight of steam used per half-hour during the trial was very constant. The jacket water was delivered continuously into a tank containing a considerable quantity of comparatively cool water, or water below boiling

point, which cooled it and prevented loss by evaporation. From this

first tank it overflowed into a measuring tank on a weighing machine.

Every hour the quantity of overflow, which necessarily is equal to the jacket drainage in the time, was weighed.

The coal was weighed in bags adjusted to 112 lbs. each. These bags were supplied to the stoker as required. At starting the trial the hoppers of the Bennis stokers were emptied and refilled with weighed coal. At the end of the trial the hoppers were again emptied, and the coal found in them was weighed back. The steam pressure was steady, with a

falling tendency at the beginning and end of the trial, and the level in the glass water-gauges was exactly the same at the beginning and end of the

trial. The steam driving the Bennis stokers was taken from the boiler in use, and, unfortunately, cannot be allowed for in considering the boiler evaporation.

The trial was started and measurements commenced at 8 a.m., and it ended at 8 p.m. Most of the observations were taken every quarter of an hour.

Obsekvations during the Trial.

Duration of trials, hours, 12 Mean barometer, inciies, 29 61 pounds per square inch, 14-54 ,, ,,

Counter and Steam and Pump Gauges. —According to the conditions of the trial the steam consumption was determined from the air-pump and jacket discharge, and the head was ascertained from readings of two pressure gauges, taken every quarter of an hour. Total revolutions in twelve hours, .... 24,942 Revolutions per minute, . . . . .34 64 314'6 Pump delivery gauge, mean pressure, feet, . . . 27 . . . '7 ,, suction ,, ,, ,, 286-9 Head on pumps in feet, by pressure gauge, . . . Mean stea,m pressure in valve chest by gauge, in pounds per 135-96 square inch, ... . . 150-50 Mean steam pressure absolute, pounds per square inch, . H.P. receiver, 83-92 gauge ,, .... ," I-T- 2-39 „ .. ,:.... 27-79 vacuum, inches, . ,, ... 0-89 Absolute pressure in condenser, pounds per square inch, . Temperature corresponding to condenser pressure, Fahr. deg., 98 -0

Condensed Steam and Jacket Water.

Total steam through cylinders in twelve hours, . . 22,129 lbs. Totaljacket water in twelve hours, .... 4,129 lbs. Total steam in twelve hours, . .... 26,256 lbs. Cylinder steam per hour, ..... 1843 '9 lbs. Jacket steam per hour, ..... 344-1 lbs. 2188-0 lbs. Total steam per hour, . ... Jacket steam per cent, of total steam, , . 15-72 2 54 PUMPING MACHINERY.

Indicator Measurements. —Indicator diagrams were taken every half- hour from the engine cylinders, and every hour from the pumps.

Mean Effective Pressure, pounds per square inch— Top.

H.F. cylinder, . . . 49-06 LP. „ ... 17-14 9-46 ri.P. ,, ... icated Eorse- —

WATERWORKS ENGINES. 255

Tf the jacliet water had been returned to the boiler instead of being dehvered to waste, as would be the case in ordinary working, then the

evaporation would have been as follows :

Temperature of jacket water, . . . . 297-0 deg. Fahr. Jacket water per hour .... 344-1 lbs. Evaporation equivalent to jacket heat supply per hour, 69-4 lbs. Evaporation equivalent to jacket heat supply per pound of coal used, ...... 0-234 lbs. Evaporation from and at 212 degrees, allowing for heat of jacket drainage per pound of coal. 8-802 lbs.

H P.Cy\inde.r

Fig. 230. — Indicator Diagi'ams from Triple-Expansion Pumping- Engine—Leeds Waterworks.

The evaporation of the boilers was not very good, even allowing for the fact that steam was supplied to the engine driving the Bennis stokers, which

is not taken into account. It appears that hard Welsh coal is not well adapted for sprinkling stokers. The boiler grate was also larger than desirable for the most economical results.

Thermal Results. Temperature of boiler steam, .... 359-63 deg. Fahr. Temperature of jacket drainage. 297-00 Temperature of condenser, 98-00 „ Total heat of steam supplied to enf;ine reckoned from exhaust temperature, per pound thermal units, 1125-6 256 PUMPING MACHINERY

Liquid heat of jacket drainage returned to boilers, reckoned from exhaust temperature, per pound thermal units,* 201-0 Pounds of steam supplied per minute. 36-47 Pounds of jacket drainage per minute. 5-74 Heat supplied in boiler steam per minute, 41,050 T.U. Heat returned in jacket drainage, 1,153 T.U. Net heat supplied per minute. 39,897 T.U.

Per Min.

Lbs. of Steam /In Cilindees.

used by Engine. \ In Jackets.

Total,

CyI/Indbr Volumes ; / Vol. described by Pistons. Cubic Feet \Mean clearance volume. WATERWORKS ENGINES. 257

Duty of the Engine. —In this country the duty is estimated as the

ffective work of the engine in ft. lbs., per 112 lbs. of coal. The effective

work in the trial was 167-6x1,980,000 = 331,850,000 ft. lbs. per hour.

The actual coal consumption was 296'5 lbs. per hour. Hence the actual duty was 125,350,000 ft. lbs. per 112 lbs. of coal. This is a very good but not exceptional duty.

In this trial, the efficiency of the boiler was not good, and the duty

which depends on the performance of the boiler and engine is not so good as it would have been if steam had been supplied by a more efficient boiler. "With a good boiler, hand fired with Welsh coal, the evaporation might very well have been 9 '5 lbs. per pound of coal. Then the coal con- sumption would have been 240'8 lbs. per hour. In that case the duty would have been 154,350,000 ft. lbs. per 112 lbs. of coal. This is an exceptionally high duty.

In America, it is common to reckon the duty of a pumping engine as the ft. lbs. of effective work per 1000 lbs. of steam supplied to the engine.

Taking this measure the duty of the engine is 151,670,000 ft. lbs. This is almost as high a duty as has ever been recorded. It involves no assumption as to the performance of the boiler. Fig. 230 shows a set of indicator diagrams which corresponded most nearly to the mean power of each cylinder; and fig. 231 is an enlargement of these diagrams to a common scale of volumes, with the saturation lines drawn both for the cylinder steam and for the total steam supplied to the engine. Fig. 232 represents a compound inverted direct-acting engine working with a boiler pressure of 70 lbs. per sq. in. It has cylinders 33 and

60 in. in diameter, a 10-ft. stroke and 26-in. pumps ; its capacity is

6,000,000 gallons of water per day to a height of 260 ft. The pump valves are of the hat-band type. The pumps have plungers weighted to the full resistance, the weight performing the function of a fly-wheel in admitting of expansive working, as explained in the chapter on the general principles. The engines and pumps are coupled together by means of a parallel motion, shown in detail in fig. 233. This motion is more perfect when the outer ends of the outer beams are guided in horizontal slides, instead of being attached to links (see fig. 100, Chap. VI.), but the link secures sufficient accuracy for practical purposes.

In fig. 234 is shown a triple compound horizontal engine actuating well pumps by means of rocking discs with varying stroke, the principle of which is explained in Chap. IV., fig. 75.

Fig. 235 is a horizontal cross compound pumping-engine such as is often used for town water supply. It has cylinders 24 in. and 41 in. in diameter and a 5-ft. stroke, and actuates two double-acting piston pumps. To get the best economy from this type of engine it should be worked on the receiver system with a cut-ofF on the low-pressure cylinder. The 17 258 PUMPING MACHINERY. engine is provided with D-slide valves, with a cut-ofF valve on the back of the main valve, the cut-off being adjustable by hand whilst the engine is

Fio. 232. —Compound Non-rotative Pumping-Engines—BirmiDgham Waterworks. 33 and 60 in. in diameter Cylinders, i , . ,

• stroke. r> o^ • J- I ylO-it. Pumps, 20 in. in diameter ) To raise 6 millions of gallons per day 260 ft. high. running. The pumps are 16 in. in diameter, and pump to a total height of 150 ft. at 35 revolutions per minute with 80 lbs. boiler pressure. The valves of the pump are small hard rubber valves working on gun-metal WATERWORKS ENGINES. 259 grid seatings and kept down by means of a light spring. There are forty- eight valves in each pump, each 7^ in. in diameter. The condenser is of the injection type, the air pump being worked from a small crank shaft driven from the crank of the low-pressure cylinder by means of a drag link.

Fig. 236 represents a compound steam pump having cylinders 26 in. and 37 in. in diameter and a 5-ft. stroke. It was designed by the author to work from a set of boilers at 130 lbs. pressure, and to exhaust into a battery of boilers at 20 lbs. pressure, supplying several Cornish engines. In this way economy was secured at a small capital outlay as the low- pressure engines and boilers already existed and worked constantly. Tiie system is described in Chap. II., fig. 13.

The pump is 22 in. in diameter, and at fifteen double strokes per

FrG. 233. —Parallel Motion Beams for Compound Pumping-Engines.

minute pumps 3,000,000 gallons per day against a head of 220 ft. The valves are of vulcanite, each 4^ in. in diameter, working on a gun-metal seating, and kept in place by a light spring.

Fig. 237 is a drawing of a horizontal compound Cornish engine actuating a single-acting bucket pump. The pump is suspended by steel rods and screws in a well to a depth of 220 ft. The wooden gantry is for the purpose of supporting and lowering the pump.

When the water is not being pumped it rises to the top of the well.

The pump was lowered through the water and worked while still suspended in the rods. By pumping, the water was lowered to the level of the pump barrel ; at that depth bearers were put in to take the weight of the pump, while the rods and screws were allowed to remain for the purpose of drawing the pump when necessary, as the pump itself was not fastened down to the bearers. 26o PUMPING MACHINERY.

LAVAWj^^AWl/sl*>lf>UAyj-^ 'v^:mm^

rn WATERWORKS ENGINES. 261

The engine has cylinders 25 in. and 54 in. in diameter, and a 5-ft. stroke. The pump is 24 in. in diameter and has a 5-ft. stroke, and delivers its water to a reservoir above the top of the well two miles distant, the total lift on the pump being 290 ft. The boiler pressure is 130 lbs. The pump valves are of the ordinary double-beat type. Fig. 238 is a drawing of a triple compound American engine designed by Leavitt. This engine has cylinders 13'7 in., 24-375 in., and 39 in. in diameter, all having a stroke of 6 ft. On a trial it is reported to have raised 12,350 gallons per minute 137 ft. high at 59'59 revolutions per minute with a steam pressure of 157'7 lbs. The consumption of feed water was 12-25, and of dry steam 11-2 lbs. per I.H.P. per hour, which is equal to an efficiency ratio of about 68 per cent. The pump plungers are

17-5 in. in diameter, have a 4-ft. stroke, and are three in number. Bore-hole Wells for Town Water Supply.—In procuring water for town

Fig. 235. —Cross Compound Rotative Pumping-Engine—-Shanghai Waterworks.

Cylinders, and 41 in. 24 diameter „ t; 1 fr t k Pumps, 16 in. diameter J

To pump a total height of 150 ft. at a speed of 35 revolutions per minute.

Boiler pressure, 80 lbs.

water supply, it is the usual and necessary practice to provide duplicate pumping-engines, and where two engines are made to pump from the same well, the well must be very large that it may accommodate two sets of pumps.

Such wells are usually 12 to 14 ft. in diameter.

To sink such a well in the ordinary way is a very long and costly undertaking, especially if soft strata are met with, where lining becomes necessary. On the completion of the well it may be necessary to drive adits to increase the water supply. A simple bore-hole is made very cheajily, and very expeditiously. Four 30-in. bore-holes can be put down in a very small fraction of the time required to sink a 1 2-ft. well. Instead of making a large well, the author puts down four bore-holes to accommodate the pumps for duplicate pumping engines—a pair of pumps to each engine, as in figs. 239 and 240. The bore-holes being completed, the pumps are lowered into them, and 262 PUMPING MACHINERY.

o a

M -o

I

o

I

v; cj .-I

a WATERWORKS ENGINES. 263

J§$i:$;$$?^m?^^:S$^^

I 264 PUMPING MACHINEEY.

Fia. 238.—Leavitt's Triple-expansion Pumping-eugine. WATERWORKS ENGINES. 265

Gors HoU Sjstam^. Tofrti WaccrSupplj

Fig. 239. Eig. 240.

Figs. 239 and 240.—Davey's Bore-hole System of Wells for Town Water Supply. 266 PUMPING MACHINERY. WATERWORKS ENGINES. 267 coupled up to the permanent engines. Immediately that is done the water found in the bore-holes can be pumped and supplied to the town. Should it be insufficient, then a small well would be sunk in dry ground to the bottom of the bore-hole pumps. The water being kept down by the pumps, the bore-holes at the level of the pumps would be connected to the centre well, and adits driven to collect more water. Should the bore-holes yield sufficient water, it would not be necessary to sink the well. It would be absurd to advocate any particular system of well-sinking as being universally applicable ; this system, however, of making wells offers advantages under favourable conditions, but the advisability of its

F18. 242

Fio. 243

Figs. 242 and 243. —Triple Compound Steam Pumps. adoption in any particular case must be a matter of judgment with the engineer planning the work. Having illustrated and described the system in outline, we will now describe a practical example of executed work. For the water supply of Widnes, bore-holes two in number are sunk in red sandstone rock, and are placed 20 ft. apart, each bored to a diameter of 30 in. for a depth of 200 ft., and to a reduced diameter of 18 in. for a further depth of 200 ft. and 300 ft. respectively, thus making the first hole 400 ft. deep and the second one 500 ft. deep. On the completion of the boring the water stood 70 to 80 ft. from the surface of the ground, when the quantity pumped by an old engine on the same site was 1-^ million gallons per day. The main pumps were then lowered into the bore-holes, each pump extending to the bottom of the large part of the hole 200 ft. from the ground level. In that position the pumps were suspended from a cast-iron bed-plate supported on a concrete foundation formed round the top of the holes, a block of oak being inserted between the head of the pump and the bed-plate. In this suspended position the pumps work. 268 PUMPING MACHINERY.

It must be observed that no temporary pumping plant being required, the main engines were erected whilst the bore-holes were being made, so that on the completion of erection of the engines and pumps, water could be at once supplied to the town, but it remained to be proved what was the quantity of water available. The engines were made for the purpose of pumping 2\ million gallons per day, but it was found that working up to their full capacity of 2f million gallons, the full yield of the bore-hole was not reached. On starting the new pximps it was found that when pumping 2| million 3

Fig. 244. —American Triple-expansion Puniping-Eiigine. gallons per day, the water level was lowered to 100 ft. from the surface of the ground. Had the yield of water been insufficient, then whatever water there was might have been sent continuously to the town, whilst the small well A shown in fig. 239 was sunk, and adits driven, say, to a depth of 180 or

200 ft. from the surface for the purpose of collecting more water. In chalk this would probably have been necessary, but in this and in other cases in sandstone it has not been necessary to drive adits. Similar bore- holes and pumps have been put down in red sandstone at Fleetwood, Kingswinford, and other places. The motive power consists of a 230 H.P. compound surface-condensing WATERWORKS ENGINES. 269 engine employed to pump from the bore-holes into a masonry tank by the

Engine House 50-0 Lonc-

ti7".D-.:. - -.f. a;:::.v."o..„,.„ lii

Fig. 245. —Compound Non-rotative Pumping-Engines—Cambridge Sewage Worts.

engine foundations, from which tank the water is forced by the same

engine to a reservoir at an elevation of 260 ft. 2 70 PUMPING MACHINERY.

The engine is illustrated in fig. 241 . It works the force pump by means of

Fig. 246.

Figs. 246 and 247. —Method of lowering pumps in deep wells for town water supply. a tail rod from the low-pressure cylinder, and the bore-hole pumps by means of compensating rocking levers actuated by a connecting rod from the crosshead —

WATERWORKS ENGINES. 271 of the engine. The principle of the compensating lever is described in

Chap. IV., p. 86.

Steam Distribution. — The engine is of the receiver type, having separate expansion valves on both high- and low-pressure cylinders, adjustable by hand whilst the engine is in motion. Description of the Engine. —Both the steam cylinders are completely jacketed, bodies and ends, with steam at boiler pressure. The valve gear consists of a D-slide valve on each cylinder actuated by means of a rocking shaft deriving its motion from a water cylinder worked by pressure from the pumping main. This arrangement has several advantages, one of which is that, should the water main burst, the engine suddenly stops of itself. On the back of each of the D valves is a pair of Meyer expansion valves actuated by means of a rocking shaft, deriving its motion from the engine itself. The main valves move uniformly and independent of the engine. The expansion valve rests on the back of the main valve, and is moved by the engine. Both travel in the same direction, and the quicker the engine goes, the quicker will the expansion valve cover the port ; with no load on the engine it covers the port instantly the port begins to open, because the engine motion then responds very promptly to the opening of the port.

Between the engine and the surface condenser is placed a feed-water heater which raises the feed water to a temperature of 110° Fahr. before it passes into the boiler. The bore-hole pumps are made of lap-welded steel tubes with wrought- iron flanges screwed on.

A steam winch is provided for drawing the pump rods, and for changing the working parts of the pumps. For indicating the water level in the bore-holes, a pipe is put down outside the pumps. At the top of the pipe in the engine-room is fixed a sensitive pressure gauge ; below the gauge is a branch communicating with a small air-pump worked by the engine. The pipe is thus kept filled with air, and the hydrostatic pressure on the outside of the tube is thus shown on the pressure gauge. The following summary gives the general particulars of a trial of this engine and cost of the installation :

70 lbs. per sq. in. Steam pressure, . Diameter of cylinders. 32 and 60 in. Length of stroke, 6 ft. 3 in. in. Diameter of force pump, . 184

Height of lift, 260 ft Length of stroke. 6 ft. 3 in. Diameter of bore-hole pumps, 184 in. 100 ft. Height of lift, . Length of stroke. C ft. 6 in. Number of strokes per minute, 272 PUMPING MACHINERY.

Depth of bore-holes, WATERWORKS ENGINES. 273 —

2 74 PUMPING MACHINERY.

The bore-hole pumps are placed at a depth of 300 ft. from the surface, but the yield of the bore-holes has proved so plentiful that at present the water level is only 67 ft. from the surface. The engine was built for a head of 160 ft. on the force pump, but, owing to the exigencies of the Water Company, has for some months past been delivering against a head of

326 ft., or slightly more than twice that for which it was designed. The engine is fitted with the differential gear. This gear, which operates the steam valves of the engine, is driven by water taken from the rising main, so that in case of a burst pipe the gear is thrown out of action and the steam valves remain closed. As an additional precaution, a throttle valve is placed on the steam pipe, which, usually full open, is arranged to close automatically, either in the event of an excessive or a too low pressure in the delivery mains. The engine is also fitted with a pausing gear, so that the speed can be at any moment regulated from two to fourteen strokes per minute to suit the demand for water for the time being. As above stated, the bucket pumps are placed in the bore-holes at a depth of 300 ft. from the surface. The buckets and clacks are of the double-beat type. The latter are not driven into their seats, but are simply secured by weights cottered to the clack spindles. They can therefore be very readily drawn to the surface at any time for examination or repair. In practice the time required for the withdrawal and replacement of one of these clacks from a depth of 300 ft. is rather less than one hour, while a set of rods and buckets can be drawn and replaced in twelve hours. The bucket seating consists of a gutta- percha ring of rectangular section, and it is found that both buckets and clacks run night and day for about twelve months without attention. The force pump, which is of the piston type, is fitted with valves of the same class as those of the bucket pumps. The horizontal motion of the engine pistons is converted into the vertical motion of the pump buckets through the high-duty attachment, which consists of a pair of angle quadrants having the pins to which the engine and pump connecting-rods are attached so placed relatively to each other that in each stroke the engine pistons obtain a mechanical advantage over the pump buckets as the stroke is made, thus permitting a high degree of expansion without the introduction of special appliances or heavy moving parts. A twenty-four hours' continuous trial of the ermine was made by Mr Douglass, the Water Company's assistant engineer. The steam consumption was measured from the air-pump discharge and jacket discharge, which were collected in tanks and carefully weighed. The water pumped was measured from the net displacement of the force pump after deducting the amount used to drive the differential gear. The following are the par-

ticulars of this trial :

Duration of trial, ...... 24 hours. lbs. Average steam pressure by gauge in boiler-house, . 145'8 in. Arerage vacuum by gauge in engine-house, . 27'4 —

WATERWORKS ENGINES. 275

Average head on bore-hole pumps, .... 67-27 ft. Average head on force pump, .... 326-4 ft. Total head, .... 393-67 ft. Net gallons delivered in twenty-four hours after deduct- ing the amount consumed by gear, 1,569,110 gallons. Equivalent average horse-power in water lifted. 129-98 Average indicated horse-power, .... 163-8 Efficiency, ...... 79-3 per cent. Average steam consumption per hour in lbs.. 2-345 Average lbs. of steam per indicated horse-power per hour, . 14-3 Average lbs. of steam per actual horse-power in water lifted per hour, ...... 18 Duty in millions per 1120 lbs. of steam used, 122-9

The total cost per annum of working this pumping station, including coal, stores, wages, renewals, and repairs, has been found to be .£10, 14s. 6d. • per actual average horse-power in water lifted throughout the year. In

other words, 6800 gallons is raised 100 ft. for the total cost of one penny.

Capital charges are omitted, but the station is a cheap one. Costs of Working Pumping-Engines.—Short trials of pumping-engines have their uses, but the actual cost must be taken over a considerable period to be of commercial value. We give below the actual cost of working two colliery pumping-engines, at the South Staffordshire mines drainage stations, taken over a period of thirteen years. The engines are compound differential engines working with steam of from 60 to 70 lbs. boiler pressure. As no other engines (excepting small winding engines used occasionally when examining pit, and capstan engines for shaft work) took steam from the same boilers, the results are more accurate than can

be obtained at many collieries. (1) The larger of the two engines, called the Bradley engine, has high- and low-pressure steam cylinders 52 and 90

in. in diameter respectively, -^N'ith a stroke of 10 ft. ; and it works two

plunger- pumps, each 27 in. in diameter, also with a stroke of 10 ft. This engine was put to work in April 1885, but separate cost accounts were not kept until the year ending June 30, 1890. In the thirteen years from that time until June 30, 1902, the engine had raised 11,686,000,000 gallons

of -water from a depth of 384 ft., equivalent to an average continuous night- and-day horse-power, in the water lifted, of 199, and to an average continuous piston speed of 61 ft. per minute. The average annual cost of working the Bradley pumping engine during the whole period has been as

follows : Per continuous pump horse-power per annum.

£ s. d. 7 2 11 4 7 10 10 11 1 4 10

£12 16 8 —

276 PUMPING MACHINERY.

(2) The smaller of the two engines, called the Moat engine, has high- and low-pressure cylinders, 44 and 76 in. in diameter respectively, with a stroke of 10 ft. ; and it works two ram pumps, 19 in. in diameter, and below them a pair of bucket pumps, 19J in. in diameter, having a stroke of 10 ft., and with a total joint lift of 620 ft. This engine was started work in 1885, but separate cost accounts were not kept until the year ending June 30, 1893. In the ten years from that time up to June 30, 1902, this engine has raised 7,391,525,000 gallons of water from a depth of 620 ft., equivalent to a continuous night-and-day horse-power of 264 in the water lifted, and to an average continuous piston speed of 115 ft. per minute. The average cost of working the Moat pumping-engine during the whole period has been as follows : Per continuous Per pump horse-power annum. per annum.

£ £ s. d. Coal, .... 1410 5 6 10 Labour, 918 3 9 6

Stores, including oil and packing, 98 7 5

Repairs to engine and pumps, . 150 11 5 Repairs to boilers. 23 19

Totals, £2599 £9 16 11

It may be remarked that the cylinders and other parts of the Bradley and Moat pumping-engines are in excellent order, and that no important parts of either engines or pumps have at any time been replaced, with the exception of the pump clack boxes—seven of which have been renewed. WATERWORKS ENGINES. 277

Annual Cost of Working Engines of Different Types.

Name, .... 278 PUMPING MACHINERY.

Trial Duties of Pumping Engines.

g Cylinders, Duuble- Engine. Trial by made Acting. II Diameter.

i CM

Milwaukee, Prof. Thurston, 28in., 48in. and 74 in.

Leeds, Prof. Unwin, . . 16 in., 25 in. and 40 iu.

Liverpool, Mr Jones and 15 in., 23 in. Mr Towler. and 38 in.

Chumka, Mr T. Platts, 15 in., 25 in. Engineer - in and 40 in. Chief, Odessa Municipality.

Dniester, First Mr T. Platts, 12 in., 20 in. Filter Engine. and 31 in.

Dniester, Second Mr T. Platts, 12 in., 20 in. Filter Engine. and 31 in.

Dniester, First Mr T. Platts, 20 in., 36 in. Forcing Engine. and 54 in.

Dniester, Second Mr T. Platts, 20 in., 36 in., Forcing Engine. and 54 in.

Melbourne, Sew- Mr W. Thwaites, 20 in., 36 in. age Pumping- Engineer - in and 54 in.

Ch ie f, Melbourn e [To fnce page 278.

;

OHAPTEE XIV.

PUMPING-ENGINE ECONOMY AND TEIALS OF PUMPING MACHINERY.

Trials of Pumping-Engines. —In Chap. II. we have discussed the rela- tive economies which should be derived from steam of different pressures, assuming that the engines were all equally efiioient for the pressures employed. All other things being the same, higher steam pressure secures greater economy per I.H.P. because there is more worli obtainable from 1 lb. of high-pressure than from 1 lb. of low-pressure steam ; therefore in drawing conclusions from steam-engine trials the steam pressures employed must be taken into account. In other words the efficiency ratio should be known.

In Chap. II. is given a summary of trials of pumping-engines, as also the efficiency ratio. The efficiency ratio is the relation between the per- formance of the engine tested and that of a perfect steam-engine working without loss, and having the same initial and exhaust pressures.

The tables give a summary of results of many reported trials, but it may be remarked that all who have had considerable experience in steam- engine trials know' that small errors occur if great care is not taken. There may be undetected leakages in valves and piston, or the steam may not be what is called dry on admission, without its being observed, and the efficiency ratio of that particular engine may be low in consequence. The same type of engine better fitted and worked with drier steam would give better results. Engine trials are exceedingly useful, both scientifically and practically but the engineer has to take into account the local conditions of the apph- cation of the engine, the capital expenditure, cost of upkeep, etc., in selecting the machinery to be employed. It must also be observed that the particular conditions under which the engine is to be worked may make it necessary to use a system of steam distribution which does not give a high efficiency ratio, as in tlie case of mining engines having heavy pit-work, where it is expedient to work compound engines on the WooU distribution of steam, and not on the receiver system, for many practical reasons. 279 : , ,

2'8o PUMPING MACHINERY.

Odessa Water Works—Dniester Pumping Station.

Official Tkial, made ey Theodore Platts, 22nd April 1903, of a Triple- Expansion Inverted Vertical Corliss Three-Crank Rotative Pumping- Engine.

No. 1 Forcing Engine.

Duration of Trial, 6 hours.

Service. —To force 5J million gallons of water in twenty-four hours against a head

of from 380 ft. to 460 ft., including friction.

Dimensions of Engine and Boilers,

Engine.

Diameter of cylinders, ..... 20 in. , 36 in. , and 54 in.

One piston-rod to each cylinder. 5 in. in diameter.

Effective piston area, high-pressure, top, 314-16 sq. :

,, ,, ,, bottom, 294-53

,, ,, intermediate-pressure, top, 1017-9

,, ,, ,, bottom 998-3

,, ,, low-pressure, top, 2290-2 bottom. 2270-6

Stroke, 3 ft. 6 in.

Diameter of pumji-rams, 17 in.

Mean area, . 226-98 sq. in.

Stroke, 3 ft. 6 in. Mean ratio of steam cylinders, 1:3-32:7-5

Volume described by high-pressure piston per stroke, 7-39 cub. ft.

,, ,, intermediate-pressure piston per stroke, 24-5 „ low-pressure piston per stroke. 55-42 , , ,,

Mean clearance volume, high pressure, 114 cub. ft., or

1-51 per cent.

,, ,, intermediate pressure, •271 cub. ft., or 1-09 per cent. "545 ,, „ low pressure. cub. ft., or •97 per cent.

Boilers.

Babcock and Wilcox type, with superheatei's ; 54 tubes, 4

in. in diameter, 18 ft. long each ; drum 3 ft. in diameter,

24 ft. long. Number of boilers under steam, .... Total heating surface, .... 4872 sq. ft Total grate area, ...... 92 „

Cliimncy Height, ...... 140 ft. Internal diameter, ....-• 6-6 „ Natural. Draught, .... • • :: : : :

PUMPING-ENGINE ECONOMY. 281

Econmniser

320 pipes, 4 in. in diameter, 9 ft. long.

Total heating surface. 2880 sq. ft

Superheater

Total heating surface, 568

Cmmter and Gauge Headings :

Total revolutions in six hours, 13,639 Revolutions per minute, 37-88

Pump delivery gauge, mean pressure, 300 ft.

suction ,, ,, ,, 20 ft. below gauge.

Head on pumps in feet by pressure gauges, 320 ft.

Mean steam pressure—absolute, 195 lbs. per sq. in.

,, ,, in high-pressure receiver (actual), 27

- „ ,, in intermediate pressure receiver (actual). 2

Mean vacuum in condenser. 27-75 in.

Absolute xjressure in condenser. 0-89 lbs. per sq. in. Temperature corresponding to condenser pressure. 98 deg. Fahr.

Condensed Steam and Jacket IVater

Total steam through cylinders in six hours, 24,660 lbs. in six ,, jacket steam hours, 3,736 „

,, steam in six hours. 28,396 ,,

Cylinder steam per hour. 4,110 ,, Jacket steam per hour. 622-6 „

Total steam per hour, 4732-6 ,,

Jacket steam per cent, of total steam, 13-15 per cent.

Indicator Measurements

High-pressure cylinder. 151-31 I.H.P

Intermediate- pressure cylinder, 123-758 ,, Low-pressure cylinder, 141-833 „ Total indicated horse-power. 416-901

High-pressure pump, 128-577 ,, Intermediate-pressure pump, 128-76

Low-pressure pump. 127-301 „ Total indicated pump horse-power, 384-638

Engine Results

Water pumped in six hours, slip neglected 1,408,334-4 gals. slip ,, ,, per hour, neglected, 234,722-4 „

Effective head by gauges, . 320 ft. Pump horse-power by pressure-gauges. 379-35

Consumption of steam per hour. 4732-6 lbs. Steam per pump horse-power hour, 12-47 „ Indicated horse-power. 416-901 : ,

282 PUMPING MACHINERY.

Steam per indicated horse-power hour, . . , 11 '35 lbs. T p TT p Mechanical efficiency ---.1—^ , .... 92 -26 per cent.

P.H.P. in water lifted >> > , TT p ' . . 91 per cent.

Heat transferred to feed water per pound of fuel, . . 638'9 B.T.XJ. Heat transmitted per square foot of heating surface per tour, ...... 124-2 „

Superheater :

Weight of steam entering per hour, . . . 4732 '6 lbs.

Temperature of steam into superheater, . . . 379'6 deg. F.

,, ,, out of superheater, . . . 428 ,,

Amount of superheat, . . . . . 48'4 ,,

Heat transferred to steam per pound of fuel, . . 196'3 B.T.U. Heat transmitted per square foot of heating surface per hour, 193-5 ...... ,, Summary

Heat transferred to boiler per pound of fuel, . . 8686 B.T.U.

„ ,, feed ,, ,, . . 638-9 „

,, ,, steam by superheat, . . . 196-3 ,,

Total heat from 1 lb. of fuel, . . . 9521-2 „

Efficiency of boiler, eoonomiser, and superheater combined, 75 per cent.

Total equivalent evaporation from and at 212 degs. Fahr. 9-85 lbs.

Thermal Results : Temperature of steam at engine, .... 384-8 degs. Fahr. saturated steam (180 lbs. per square inch), 379'6 ,,

Superheat at engine, . . . . . 5-2 ,,

Temperature of condenser (exhaust), . . . 98 ,,

Total heat of steam supplied to engine reckoned from

exhaust temperature per pound, . . . 1134-2 B.T.U.

Liquid heat returned to boiler in feed water vid eoonomiser

by jacket drains from exhaust temperature per pound, . 254-3 ,,

Jacket water supplied to boiler per minute, . . 10-37 lbs. Heat supplied by boiler steam, .... 89,454-3 B.T.U.

Heat returned to boiler by jacket drains per minute, 2637 '1 ,,

Net heat supply per minute, . . . 86,817-2 ,,

Heat supply per indicated horse-power per minute, . 208-2

,, water horse-power per minute, . . 228 5 ,,

Heat equivalent of indicated work per minute, . . 17,683 ,,

Thermal efficiency of indicated work, . . . 20-3 per cent.

Heat equivalent of actual work done per minute, . . 16,088 B.T.U.

Thermal efficiency of actual work done per minute, . 18-5 per cent.

Duty of the Engine : Actual duty per 112 lbs. of coal, .... 150,222,000 ft. lbs.

,, 1000 lbs. of steam. . . . 158,716,000 „ PtTMPING-ENGINE ECONOMY. 283

Waltham Abbey Pumping-Bngine. — Fig. 249 illustrates a triple compound engine of the marine type, one of the first engines of the class used by Mr. W. Bryan at the Waltham Abbey Pumping Station of tlie East London Waterworks. Mr. Bryan and the author made a trial of this engine with the following results.*

The engine on which the experiment was made is a triple-expansion surface-condensing engine of the ordinary inverted direct-acting marine

'W/v/nnii/////^/' Fig. 249. —Triple-expansion Pumping-Engine, East London Waterworks, ^¥altllam Abbey.

type. It was fully described and illustrated in Engineering, 8th August

1890, pp. 158 and 162. The diameters of the cylinders are 18, 30'5, and 51 in. respectively. The stroke of each of the three cylinders is 36 in. Each piston cross-head is connected to its crank by a single connecting rod, and to a plunger pump by a pair of pump rods. There are thus three steam cylinders, three connecting rods, three pairs of pump rods, and three pump plungers. Each of the three cylinders is provided with an ordinary slide valve actuated by a separate eccentric on the crank shaft. The slide valve on the high-pressure cylinder is actuated direct by its eccentric and is provided with a I\Ieyer expansion

* Proc. Insl, MccliMnical Engineers, 1894. 284 PUMPING MACHINERY. valve, by means of which the speed of the engine was regulated during the experiment. The slide-valves on the intermediate and low-pressure cylinders are actuated through variable expansion links, the positions of which remain unchanged throughout the trial. The crank shaft is placed above the pumps, and the cranks rotate in the sequence—high, low, intermediate. The fly-wheel is placed towards one end of the crank shaft, and beyond it there is fixed a crank actuating a pair of well pumps by means of rocking quadrants. The bodies and both ends of all three cylinders are steam jacketed, the cylinders forming liners in the body-jackets.

Steam is supplied to these jackets through a pipe connected to the main steam-pipe on the boiler side of the stop valve. The steam to the jackets enters at the top on one side, and at the bottom on the opposite side ; and in ordinary working the high-pressure jackets discharge directly into the boiler while the intermediate and low-pressure jackets discharge through steam-traps into the hot well. The jackets of the high-pressure cylinder receive steam at full boiler pressure, and by means of reducing valves the pressures in the jackets of the intermediate and low-pressure cylinders are maintained a little higher than the pressures in their respec- tive valve-chests.

Each cylinder is therefore jacketed with steam a little above its own initial pressure. Duration of experiment, .... PUMPING-ENGINE ECONOMY. 285

Lea Bridge Ptunping-Engme. —Fig. 250 represents in outline a triple- expansion compound engine of the inverted marine type designed by Mr. W. Bryan, two of which have been erected at the Lea Bridge Pumping Station of the East London Waterworks. A trial of this engine was reported in the Proceedings of the Institution of Mechanical Engineers, 1894, from which report we extract the following results. Description of Engines. —The engines tested were two in number, dupli-

cates of each other. The cylinders are 20-03, 33-99, and 57-05 in. in

Fig. 260. —Triple-expansion Pumping-Engine, East London Waterworks, Lea Bridge. diameter respectively, each having a stroke of 48 in. The piston rods are each 5 in. in diameter, and the pump plungers, which form prolongations of the piston rods, are 30 in. in diameter, each plunger having a displacement of 122-4 gallons per revolution. The crank shafts are placed under the pumps and revolve in the sequence—high, low, intermediate. All the cylinders are provided with Corliss valves and the Corliss cut-off; the latter, however, is not \mder the control of a governor, but is regulated by hand whilst the engine is 286 PUMPING MACHINERY.

running. Each engine is provided with its own surface condenser having 1053 square ft. of cooling surface, and the steam passing through the engine during the trials was measured by the air-pump discharge. The water from the jackets of each cylinder was measured separately. The two engines experimented with are named 'North' and 'Central,' from their positions in the engine house.

Jacketing. —Each cylinder has a jacket on the body, and one on each of the ends, the body jacket having a steam space of one inch. Drain pipes were provided, so that the water drained from the jackets of each cylinder could be measured separately. The pressure in any jacket could be varied by means of reducing valves. Clothing.—The cyUnders and steam pipes are clothed with about 2|- in. of ordinary composition, with the exception of the bottom covers, which are not clothed.

Remits and Comparisons. —In the following table the thirteen trials are divided into three groups, and are arranged in these groups in their order of merit, according to the total consumption of steam per indicated

H.P. per hour ; the steam pressures in the boilers and jackets are added.

Steam-pressures, lbs. per sq. in. above atmosph PUMPING-ENGINE ECONOMY. 287

Power Co., and the following results of a trial are taken from a paper

Fio. 251. —Triple-expansion Pnmping-Engine, London Hj'draulic Power Co., Wapping Pumping Station. by Mr. Ellington in the Minutes of Proceedings of the Institution of Oivil Engineers.

Trials of a Tkiple-expansion" Compound Vertical Sitrface- Condensing Steam Pumping-Enginb and Faikbairn-Beeley Boiler at the Wapping Pumping Station of the London Hydraulic Power Company. ,

2 OS PUMPING MACHINERY.

Tkials of a Triple-expansion Compound Vertical Surface-Condensing Steam Pcmping-Engine and Fairbaien-Beeley Boiler at the 'Wapping Pumping Station or the London Hydraulic Po-wer Company—continued.

March 7, March 11, March 18, March 25, 1892. 1892. 1892. 1892.

Coal.

Quality, (Inland) (Nixon's Navigation.)

Total weight fed on to grates, . lbs. 3287 3744

, of clinker, etc. , . . , 114 162 , , , " Fuel burnt per hour (including clinker, etc.), lbs. _

Fuel burnt per square foot of grate, ,,

,, consumed per I. H. P. per hour, ,, Calorific value of dry coal, lbs. of -water per lb. of coal

Feed-water.

Feed temperature on entering economiser, ) ° Fahr. |

Feed temperature on entering boiler, j ° Fahr. ( Heating surface of economiser, sq. ft.

Total water evaporated, . . . lbs.

Water evaporated per lb. of fuel (wet), ,, (dry), 1 from and at 212° (calculated) lbs., . J Thermal efficiency of boiler, including | economiser, . . . per cent. ) ' Amount of feed- water per I.H.P. per

hour (engine), . . . lbs. Steam-pipe condensation and loss * per

I. H. P. per hour, . . . lbs. Total feed-water, ..... Total quantity of water pumped, gallons.

Accumulator pressure, . lbs. per sq. in. "Water pumped per cwt. of coal consumed, gallons , ,

PUMPING- ENGINE ECONOMY. 289

Clearance, per cent. , low pressure, , 2

First receiver, capacity in cubic ft. , 7-8

Second „ ,, 14-1

Total steam re-heating surface, in sq. ft., 183-5 Number of single-acting pump rams. 3 Diameter of single-acting pump rams in in.. 22 Diameter of single-acting air pump ,, 10 feed ,1 ,, pump ,, 14 Stroke of pumps in ft., 3 Number of gallons delivered per revolution, 148

Engine Test. Average Temperatures— Engine room, Water in suction tank,

,, hot well, „ feed tank, Exhaust steam from low pressure,

Discharge from heater, . . ,

Average Pressures—

Steam gauge at separator, in lbs. Vacuum gauge, in in., .... Water-pressure gauge, ill ft.,

Height of gauge above water level in suction tank, in ft,

Total head pumped against, in ft., ,

Revolutions— Total number per counter. Per minute, ....

Steam used— Air-pump discharge, in lbs.,

,, ,, per hour. Water discharge from jacketing traps,

,, ,, ,, per hour. Total steam used, ....

,, ,, per hour. Water discharged from separator trap,

Drains from steam pipes, . Water discharged from safety valves and other leaks, Percentage of steam unaccounted for to total steam generated.

Percentage of jacket to total steam generated, ,

Average Indicated Horse-powei—

High-pressure cylinder, top, .

,, ,, bottom, . Intermediate-pressure cylinder, top,

,, ,, ,, bottom. Low-pressure cylinder, top,

,, ,, bottom.

Total, J

290 PUMPING MACHINERY.

Pump Horse-power— High pressure, .... Intermediate pressure, Low pressure, .... Total,

Friction horse-power, per cent.,

Delivered horse-power in water lifted. Mechanical efficiency,

Actual steam used per I. H.P. per hour, i.e. jacket discharge. Actual steam used per delivered horse-power per hour.

Relative Voluines of Cylinders— High-pressure cylinder. Intermediate,

Low pressure, . . .

Expansions, etc. —

Mean cut-off in high-pressure cylinder,

,, ,, intermediate ,,

,, ,, low-pressure ,, Mean total expansions. Mean terminal pressure absolute.

Pump Test—

Total gallons lifted,

I II psr hour,

,, ,, per minute,

Average height of lift in ft.,

Total ft. lbs.. Duty per cwt. of coal nsed. Duty on 1000 lbs. of steam,

Pounds of coal per I. H.P.

Pmnping-Engine at Hamptoa—Fig. 252 represents the outline of a compound engine by Mr. Restler at the Hampton station of the Southwark

and Vauxhall Water Co. Professor T. Hudson Beare's trial of it is reported in the Proceedings of the Institution of Mechanical Engineers, 1894, to which report we are indebted for the following particulars. The cylinders are 32 in. and 52 1 in. in diameter, each having a stroke

of 84 in. The piston rods are each 6 in. in diametffl-. The engines are provided with ordinary D-slide valves, one at each end of each cylinder, each D-valve having a Meyer expansion valve. The valve chests are prolonged to the ends of the cylinders, thereby securing short ports and very small clearance volumes. The main pumps are of the vertical piston type placed one under ea(rti cylinder, and are worked direct from the engine cross-heads by means of vertical rods arranged so as to pass the crank shaft. Each pump is 19 in. in diameter, and has a 7-ft. stroke and works against a head of about

180 ft. of water. PUMPING-ENGINE ECONOMY. 291

The air pump and feed pump are actuated by a beam from the cross- head of the high-pressure cylinder, and the circulating pump by a similar beam from the low-pressure cross-head. Each engine has a surface condenser containing 553 tubes 7 ft. long and 1 in. in outside diameter, with a total cooling surface of 1040 sq. ft. The diameter of the feed

Fio. 252. —Compound Pumping-Engine, Southwark and Vauxhall Water Co., Hampton.

pump is 4| in., of the air pump 24 in., and of the circulating pump 13 in., the first has a 27 in., and each of the latter has a 39 in. stroke. Before the feed water enters the boiler it passes through an economiser, and is raised some 70° or 80° in temperature.

The bodies and ends of both cylinders are jacketed ; also the receiver, steam passages, valve chests, and covers. The cylinders form liners within the body jackets. The jackets are supplied with steam by separate pipes leading from the main steam pipes. The cylinders and steam pipes 292 PUMPING MACHINERY. are coated externally with 2 in. of Leroy's non-conducting composition and lagged outside with wood.

Duration of trial, . , 5 hours.

Number of expansions, ,

Steam Pressures—

In boilers — above atmosphere, .

,, high-pressure steam jacket above atmosphere,

,, low-pressure steam jacket above atmosphere,

, intermediate receiver above atmosphere, I

,, condenser, absolute, Barometric pressure, absolute. Mean effective pressure H. P. cylinder,

LP. „ .

,, ,, total, reduced to L.P. cylinder. Revolutions per minute,

Piston speed, ft. per minute, I.H.P. high-pressure cylinder,

,, low- ,, ,, ,, total, ....

Dryness Fraction of Steam—

In high-pressure cylinder after cut-off,

,, ,, before release,

,, low-pressure ,, ,,

Air-pump Discharge Watei— Per hour, .... ,, I.H.P. per hoar, .

Jacket Watei—

From high-pressure jackets, per hour,

,, low- ,, ,, ,,

,, receiver ,, ,,

Total jacket water per hour, . .

,, per I.H.P. „

,, in per cent, of total feed water.

Feed Water, including Jacket Waier— Total per hour, ..... per I.H.P. per hour, ,, .... Saved per lb. of jacket water, . . Percentage less feed water, with steam in all the jackets,

AhsoVute Pressures, lbs. per sq. in. measured from Indicator Diagrams —

Maximum initial in high-pi'sssure cylinder, .

At cut-off in high-pressure cylinder, .

,, release ,, ,, Minimum exhaust in high-pressure cylinder, Maximum initial in low-pressure cylinder,

At release in low-pressure cylinder, .

Minimum exhaust in low-pressure cylinder, . , ,

PX7MPING-ENGINE ECONOMY. 293

Temperature range in high-pressure cylinder, . 102° Fahr.

.. » low- of „ air-pump discharge, . Boiler steam, total heat per lb.

Air-pump discharge, total heat per lb. Jacket steam, latent heat per lb..

Beat passing through Engine—

Through cylinders per stroke, jackets , , Total through engine per stroke,

Equivalent of I. H. P. ,, Thermal efficiency, 294 PUMPING MACHINERY.

Table of Experimental Eesults with and without Steam IN Jackets. PUMPING-ENGINE ECONOMY. 295 the daytime, and not on Sundays, 30 per cent, more coal is often consumed than that calculated from the results of a twelve hours' trial ; but much depends on the stoking and the boiler losses during the time the engines are stopped. The steam pipes may be of great length, and both pipes and boilers may be imperfectly clothed. No exact rules can be laid down to meet the variations which occur. Load Factor. —Various definitions have been given of the term 'load factor,' but for certain purposes the following will be found convenient.

The load factor is the ratio between the average output per hour and the maximum output in any one hour during the year.

Let a, b, c, d, fig. 253, represent to scale an area equal to the total work

a e I y^ r^y. ^ r/^ /* >: / /

H / / // //. 'y

/, V / // / / / A / / / / / A ////// X A f Time. c Fig. 253. —Diagram illustrating the term 'load factor.'

The shaded area represents work done, and the rectangle a, li, c, d the work which would have heen done if the engines had worked fully loaded the v/hole of the time. The load factor may be applied to a day's or a year's work. which the engines would have done if the mean power had been equal to the maximum during the period, the vertical line representing work and the horizontal line time ; then if the engines work fully loaded half the time, the work done would be a, e,f, d, or 50 per cent, of the whole. The load factor on this basis might then be expressed by "5 (the unit being 1), or

by ' 60 per cent.' It would not, however, have a definite meaning if the rectangle a, b, 0, d represented one year's possible work, and a, e,/, d half a year's work when no work was done during the other half of the year. The load factor is only applicable for the period during which the machinery is working.

If the speed of the engines varies, then the work done would be represented by the area enclosed within the dotted line, and the load factor by its percentage value relatively to the total area of the rectangle. 296 PUMPING MACHINERY.

The diagram may be made for a single day's work, but to be of commercial and practical value it must represent the average day's work taken over a long period. Load factors may have different constructions, according to the purpose to which they are applied.

It will be seen that unless the load factor is simply applied to questions relating to the saving in fuel or steam, the reserve power must be taken

into account, as it has a direct bearing on the capital charges and cost of

upkeep of the whole power, part of which is represented by reserve power.

' It is obvious that the term load factor ' may be made use of in several

ways. It is exceedingly useful in showing at a glance what is not so readily understood when expressed in figures.

The Birmingham hydraulic power supply is produced by means of gas engines, and the following table shows to what extent the economy of gas has been secured by increase in the output.

Year ending ;

PTJMPING-ENGINB ECONOMY. 297

case of centrifugal pumps, where the best results are obtained at a critical

speed suited to the lift. For this reason the efficiency of reciprocating pumps under variations of speed and lift is much more uniform than that of centrifugal pumps. In ordinary pumping-engines the importance of a high average pressure consistent with steam economy per I.H.P. is very great, for not only does it increase the mechanical efficiency, but it also reduces tlie percantage loss from back pressure. An additional back pressure in the condenser of 1 lb.

would be 3'3 per cent, only if the mean indicated pressure was 30 lbs.

but it would be 10 per cent, if the mean pressure was only 10 lbs. The mean pressure usually employed in Cornish and old-fashioned beam engines

was 13 lbs. per sq. in., and the economy fell off very rapidly with increase in the back pressure of the condenser. It has been shown in the ehapter on Cornish Engines that the modern double cylinder or compound Cornish engine is worked with a water load

of 30 lbs. or, say, 33 lbs. indicated. This engine starting with only half

its load would have an indicated load of 16 '5 lbs. more than the full load

of the old type of engine. Its mechanical efficiency is therefore not so much reduced by light loads and back pressure. CHAPTEE XV.

CENTRIFUGAL AND OTHER LOW-LIFT PUMPS.

Low-Lift Pumps. —Low-lift pumps are required for the drainage of lands and for many other purposes. The quantity of water to be lifted is large compared with the power. The problem presented is that of the best application of power under the circumstances. The general impression has been that a piston pump largely decreases in ef&ciency with low lifts, and that for very small lifts its efficiency is very low. If, how- ever, the lift exceeds 12 or 15 ft., the mechanical efficiency of a properly designed piston pump is as high as that of any other kind of pump for the same lift, and generally it is higher. The valid objections, however, to piston pumps for very low lifts are their larger size and the number of valves necessary.

The Scoop Wheel is a rotary pump much used for low lifts in the drainage and irrigation of lands, etc. Its application has been much restricted since the introduction of the centrifugal pump. The scoop wheel is a kind of reversed undershot water-wheel, and is illustrated in fig. 254. Signer Cuppari, in a paper in the Proceedings of the Institution of Civil Engineers, vol. Ixxv., gives the following particulars of scoop wheels in use in Holland. The Halfweg pumjDing station has six float wheels with a combined width of breast of 38 '70 ft. The external diameter of one of the wheels is

23 ft., that of the other five, 21-33. The internal radius is 5-92 ft. The floats, twenty-four in number, are inclined to the radius, so as to be tangen- tial to a circle concentric with the wheel, and having a radius of 2"85 ft.

The centre of the wheel is at 5 "6 ft. above datum. The steam-engine has four separate valves, with expansion regulated by hand (of the old double- acting Cornish type). The steam cylinder is 3'33 ft. diameter by 8'0 ft. stroke. There are three boilers always in steam, each having 538 sq. ft. of heating surface, and carrying a maximum steam pressure of three atmospheres. The driving axle is connected on each side by toothed gearing to a shaft carrying three wheels. The speed is reduced in the CENTRIFUGAL AND OTHER LOW-LIFT PUMPS. 299

ratio of 13"5 to 6. The wheels are all upon the same shaft, built up of several pieces, which oau be coupled up as required. Three systems are adopted in the construction of water-wheels, which

differ in the method of transmitting the force. In the first system the

force is transmitted by a driving-axle and spokes acting as struts ; in the second by a wheel with teeth upon the circumference, the axle and spokes

acting as struts ; and in the third by a similarly toothed wheel, but with

a double set of rods in tension instead of spokes. The Dutch still adhere

to the first system, although, according to Redtenbacher, it is not suitable

when the power is 10 or 12 H.P., as large wheels of this kind are relatively very heavy. Thus the Italian wheels at Bresega, near Adria, which are on

Fig. 254. —Scoop Wheel.

the third system, have an external diameter of 39'4 ft., an internal diameter

of 26'25 ft., and a breadth of 6-56 ft., and are the largest known in

Holland or Italy. The displacement of water is about 5300 cubic ft. per minute per wheel. The axle of these wheels has a diameter at the thickest

part of T41 ft. and T25 ft. at the bearings. The wheels at Katwijk,

which are on the first system, are only 29 5 ft. in diameter, yet the axles of the furthest wheels are of the same diameter as above. At Zeeburg, near Amsterdam, there are eight wheels of the most

recent construction, 26 ft. 3 in. in diameter and 10 ft. 8 in. across the breast. The driving-axles of the wheels furthest from the motor are

1 ft. 6 in. in diameter, and weigh over 6 tons. Each wheel has four sets. of spokes, each set weighing 4 tons. The driving-axles nearest the motor are nearly twice as heavy — —

300 PUMPING MACHINERY.

There are 282 cubic ft. of oak and 222 cubic ft. of piae timber in each wheel. Compared to the mass and weight of material, the volume of water raised, amounting to 7063 cubic ft. per minute per wheel, seems small.

The velocity of a point on the periphery is about 208 ft. per minute, which in Holland is considered moderate, but in Italy high. In this system of construction the axle is subject both to bending and torsion; in the suspension system to bending only. Mr. Zangirolami of Adria constructs wheels with curved buckets capable of raising water to a height equal to of the radius ; they give -f- excellent results. Instead of two toothed wheels, one at each side of the wheel, he puts one toothed wheel in the middle, thus avoiding the practical difficulty and expense of two cogged wheels of precisely similar pattern on the one hand, and the twisting effect produced by a single cogged wheel when placed at one end of the wheel on the other.

At Halfweg the driving-axle is of cast iron, solid, 1 ft. 2 in. in diameter near the motor and 10 in. at the further end, with enlargements at the joints. The framework of each wheel is formed of three sets of spokes, which are cast in one piece with the nave and ring, or rather each set is cast in two parts and bolted together. The whole weight of one wheel with its axle is probably about 15 tons. For the proportioning of scoop wheels Mr. Forster gives the following formula :

D = 9-82 VH, in which D is the diameter of the wheel and H the height from the bottom of the wheel to the highest level to which the water has to be raised, but Mr. Wheeler gives 8-75 ^/H as more nearly representing English practice. Sometimes the scoops are curved. The wheels at Zuidplas in Holland have curved scoops. Diameter of wheel, 32'8 ft. ; dip of scoops, 3-28 ft.; head of water, ITS ft. H in the above formula is then

ll-8 + 3-20 = 15-08ft.

The largest scoop wheel in England is 50 ft. in diameter.

The maximum speed of a point in the periph*y is usually 8 ft. per second ; 30 ft. wheels usually make 4 to 4J revs, per minute. The displacement efficiency is found to be about 80 per cent., and when driven by steam engines, the total efficiency, that is, water H.P. divided by W H P found to be about 60 per cent. ;' ' " indicated H.P., has been = -qq _

Higher efficiencies have been obtained, but much depends on the conditions of application and working. A wheel proportioned for a high lift will give a low efficiency at a low lift, and naturally so. An engine working a wheel with 2 ft. lift has been —

CENTRIFUGAL AND OTHER LOW-LIFT PUMPS. 301

found to use 5'5 lbs. of coal per W.H.P. ; but when the lift was reduced to

1 ft., it used 14 lbs. of coal, and at 6 in. lift 50 lbs. per W.H.P. Of course the increased consumption was principally due to the reduced efficiency of the steam and the reduced mechanical efficiency of the whole plant ; very little was probably due to the reduced efficiency of the wheel itself. The same thing happens with centrifugal pumps, though not to the same degree. Mr. Barker gives the following results of trials with a centrifugal pump where the lift was varied :

Lift =1 2-40 3-30 7-20 Coal per W.H.P. = 9 -37 8-22 7-71 6-60

The angle for the scoops of scoop-wheels, or floats as they are some- times called, is determined by the following consideration. The scoops usually dip from the radial line about 40 degrees, and from tangents to a circle concentric with the wheel. The centre of the

wheel is fixed so as to divide the head and dip equally, except when the lift is great. The dip is seldom more than 6 ft. The efficiency or ratio of discharge to displacement of bucket and piston pumps has been found for lifts of about 13 ft. to be 89 per

cent. ; but much will depend on the design and mode of application of the pump. Signer Cuppari gives the following as his experience in Holland.

Total useful effect, ..... Float or scoop wheels, .... Lift and force pumps, .... Centrifugal ,,

Signer Cuppari gives the relative cost per W.H.P. of pumping stations in Holland in the following table.

Scoop wheels, Screw pumps, Centrifugal pumps, .... Piston pumps, 302 PUMPING MACHINERY.

The horizontal spindle pump is usually termed a 'cased ' pump, is self-contained, and is driven from the engine by means of a belt or gearing, or is actuated direct from the engine shaft. The pumps having vertical spindles are so arranged as to be always charged or submerged in the well or shaft below the engine. To keep the horizontal spindle pump always charged it is necessary to place it in a dry well below the lowest water level, the water being supplied by a suction pipe through the side of the well.

When the pump is above the water level a charging apparatus is required, and that involves a foot valve in the suction pipe. Before the pump can deliver water it must be fully charged and all air excluded.

The charging of the pump is sometimes effected by means of a steam ejector which ejects the air, and thus draws water into the pump through the suction pipe.

The chief application of the vertical spindle pump is in draining lands, emptying and filling docks, etc. Examples of this class of pump are given further on. The action of centrifugal pumps may be thus described.

If the pump and pipes are full of water, and the fan is worked at a sufficient velocity, the centrifugal force imparted to the water in the fan will cause the water to be discharged from the fan casing into the discharge pipe, and to be drawn in from the suction pipe, thus giving rise to a continuous stream of water. To ensure a discharge, the centrifugal force must be more than is sufficient to support the full column of water. To support the column without any discharge, the velocity of the periphery of the fan must be at least equal to the velocity which a body would acquire in falling through the height of the column. Calling the velocity in feet per second V, and h the height, then V = 8 Jh, but in practice the shape of ^;he blades and the size of the fan influence the periphery speed. The velocity of the periphery of the fan necessary to support the column without discharge varies from V = 8 Jh to V = 9-5 Jh. As the velocity increases so does the discharge, but the discharge for a maximum efficiency is a matter of experiment. For results of experiments with centrifugal pumps, see the papers by Thompson and Parsons in the Proceedings of the Institution of Wivil Engineers. The " former author says : The best duty is obtained when the speed of the periphery of the fan exceeds the velocity of a falling body due to the height of the lift by from 6 to 8 ft. per second, but the duty is not very much reduced when the excess of speed falls to 4|- ft. per second or rises to 14 ft. per second, as determined by experiment with lifts varying from 5| to 20 ft." " The same author says : When a centrifugal pump, properly pro- portioned, is worked by a steam engine, the maximum duty that may CENTRIFUGAL AND OTHER LOW-LIFT PUMPS. 303 be expected is about 55 per cent, of the indicated power in tlie smaller pumps, rising in the larger ones to 70 per cent." Centrifugal pumps of modem construction vary very much in form of

A 304 PUMPING MACHINERY.

HOi^li'

4rU-——^'

Fig. 257.—Centrifugal Pump at Burnt Fen. CENTRIFUGAL AND OTHER LOW-LIFT PUMPS. 305 is obtained with properly proportioned large pumps working under favourable conditions. An allowance must always be made from the result of special trials. Although a higher percentage may be obtained under special conditions of lift and speed, such conditions cannot be maintained in ordinary work. When using the term efficiency, we must distinguish between the efficiency of the pump itself and the efficiency of the pump and engine combined. The efficiencies just named are meant

to be the combined efficiency of engine and pump, that is

Water H.P. Indicated H.P.

Let the efficiency of the pump itself be VO per cent., and that of

the engine itself 80 per cent., then the combined efficiency is 56 per cent.

The centrifugal pump is not generally used for lifts of more than 20

l-6i -+- — l-ir---*--||0'

Fig. 258. —Details of Pump Spindle and Onion Bearing of Centrifugal Pump at Burnt Fen.

to 30 ft., and experiments are wanting as to the efficiency with higher

lifts. Experiments are being made with combined pumps in which several fans are mounted on one shaft with a casing forming several pumps, one

discharging into the other, the total lift being the combined effect. Thus

three pumps, each equal to a head of 30 ft., would give a combined effect

of 90 ft. We are without any reliable data as to the efficiency of such pumps.

It is only for special purposes, where the efficiency is not of great im- portance that they are likely to be used. In special cases centrifugal pumps may be driven by electric motors or a Pelton wheel directly fixed to the spindle of the pump. Fig. 255 illustrates a pump driven by means of a Pelton wheel used in one or two instances by the author in waterworks, for lifting the water from the

storage reservoir to the filter beds, a height of from 6 to 10 ft., the 20 3o6 PUMPING MACHINERY.

power for working the Pelton wheel being obtained from the town main.

Fig. 256 is an illustration of a large centrifugal pump designed by the author for the Cambridgeshire fens. Figs. 257 and 258 give details of the pump and spindle. The fan is 6 ft. 6 in. in diameter, and 10 in. deep.

It lifts 120 tons of water per minute to a height of 12 ft., and is driven by means of a compound condensing engine. The gearing between engine

and pump is in the proportion of 1-54 to 1. The pump has a free vortex.

Above the fan is a shield to relieve the pump from pressure.

\-^K^\\~sJ^^\\\\v

Fig. 259.

The shield is suspended by means of tie rods from a girder thrown

across the well, and is held in position by means of three brackets bolted to the outer casing, the brackets having inclined surfaces

to minimize the resistance offered to the water in the well during its upward spiral motion. So largely does the shield take off the pressure from the top of the fan, that in the normal condition of running the

weight of the fan, shaft, and wheel, is almost entirely supported by the water passing through the pump. There is no thrust block on the fan —

CENTRIFUGAL AND OTHER LOW-LIFT PTJMPS. 307 spindle. The spindle is supported by the 'onion' bearing A, fig. 258, suspended from a girder. The onion is of steel. The bearing is of gun metal fastened on the top of the pump spindle. The bearing forms an oil cup. As the pump is so well balanced, there is little weight on the

' onion ' after the pump begins to deliver its water. The following table of the results of trials made with pumps having different forms of arms or blades is given in Thompson's paper :

Appold's Centrifugal Pump. 3o8 PUMPING MACHINERY.

Experimental efficiencies obtained by R. C. Parsons on a 1 4-in. revolving fan, 10-in. suction, and 10-in. discharge, made on the Appold principle. CENTRIFUGAL AND OTHER LOW-LIFT PUMPS. 309

meter horse-power ; the water horse-power divided by the dynamometer horse- power shows the efficiency of the pump being tested ; or, to formulate, Water H P ' i^ „ = the efficiencyJ of such pumpst t as are driven byj a belt. Dynamometer H.P.

Fig. 264 shows the efficiency curves for different velocities, plotted from tests made of two pumps with 5-in. apertures.

These tests were made under an average elevation of 17 ft., the pumps in both cases draughting about 9 ft. and discharging 8 ft. higher. The upper curve a b was the result of tests made with a pump that was very clean and smooth inside. The lower curve c d was made with a pump in

Fig. 261

Figs. 260 to 263. —Illustrations of Centrifugal Pumps used in Parson's Experiments.

which, through carelessness in the foundry, the core sand had been allowed to burn into the inside face of the volute or casing and water passages. The difference between these two curves (which, by the way, are remark-

ably uniform) shows the absolute necessity of having the inside of all such pump castings very smooth and free from the slightest roughness. These tests seem to show that the efficiency rises very gradually and uniformly

until the water reaches a velocity equal to 11|^ ft. per second. The

highest efficiency with a pump of this size is apparently obtained with a velocity of 12 ft. per second, after which point the efficiency falls very rapidly. 3IO PUMPING MACHINEKY.

Comparative Trials of Piston Pumps and Centrifugal Pumps.*—The establishment of Messrs. SohaefFer, Lalanoe &, Co., at Pfastatt, uses daily from 8000 to 10,000 cubic metres of water, drawn (until 1885) from the river Doller by means of ten centrifugal pumps. To obtain a supply of water with a more constaait temperature, a well was sunk in the water- bearing strata near the river, and 20 to 45 gallons per second drawn by means of two 'conjugated' centrifugal pumps supplied by Messrs. Nent & Dumont. Subsequently the means of supply were extended, and piston pumping-engines were constructed capable of drawing and delivering 90 gallons per second into the tank already constructed for the centrifugal

VELOCITv IN TEET PER SECOND 5lNCH APERTURE

a. I 40 —

CENTRIPUGAL AND OTHER LOW-LIFT PUMPS. 311

Each trial lasted from 4J minutes to 7^ minutes. The leading results were as follow :

Duty of Conjugated Centrifugal Pomps.

Trial. CHAPTEE XVI.

HYDRAULIC EAMS, PUMPING MAINS, ETC.

Hydraulic Rams are hydraulic machines by means of which water is raised by utilizing the energy of a moving column of water. If the motion of a column of water in a pipe be suddenly arrested, the energy of the

column will be spent in increasing the pressure in the pipe, and if the pipe be provided with a branch leading to a higher elevation, some of the water wiU rise in the branch, due to the increase in pressure. The energy of W V^ the column is equal to , in which W = the weight of the water and ^ 64-4 ®

V the velocity in ft. per second. Let the column be 40 ft. long with a

capacity of 4 lbs. of water per ft., and the velocity 5 ft. per second, then 160 X 25 equals an energy of 60 ft. lbs. or that required to raise I lb. of

water a height of 60 ft. ; if the utilized energy = 70 per cent., then '7 of

a lb. of water would be raised 60 ft. each time the water column

acquired the velocity of 5 ft. per second, and was suddenly arrested. The

construction of the hydraulic ram is illustrated in fig. 265.

A is a pipe from a stream or reservoir, B a valve opening downwards (which we will call the momentum valve) into the pipe C. A branch from the pipe C has an air vessel fixed on to it, and containing a non-return valve D. A pipe E conveys the water raised to the cistern. Let the valve B be opened, then the water in the pipe A will flow through until its velocity is sufficient to lift the valve B. The^said valve will then suddenly close and the energy of the moving column in the pipe A will be spent in raising some of the water through the air vessel to the cistern.

When the energy has been thus spent, a reaction is set up, the valve B falls by its own weight, and the operation repeated. During the reaction a little air is drawn in through the snifting valve S, thus keeping the air vessel charged. Hydraulic rams have been said to have given an efficiency as high as

60 to 70 per cent., but in ordinary practice the efficiency is low. The length of the pipe A is important in relation to the height to which the HYDRAULIC RAMS, PUMPING MAINS, ETC. 313

water has to be lifted. For a given fall its lengtla should be proportional

to the height of the delivery. The lift of the valve B should be adjustable.

Earns have been made to lift water by suction, by means of an

Fig. 265. —Simple Hydraulic Ram.

independent water supply. Leblanc's ram is of that kind, and is illus-

trated in fig. 266.

G is the independent source of supply of power water. It is required

^^)fi:V^'^Fir)?\-\?;:\n-^XI ;

^^mi

[T.. t T?r7?(=)?V^

Fig. 266. —Leblanc's Syphoa Hydraulic Rams.

to lift from F to E. A is a floating momentum valve, and H a non- return valve. The rush ef water through the pipe D from G causes the valve A to close. The energy of the water in D carries the water forward, 314 PUMPING MACHINERY.

and tending to form a vacuum in front of the valve H, causes the water

in C to follow the water in D ; some of the water in F passes into the pipe D, and from there to the cistern E.

When the energy of the water is spent, it commences a retrograde motion because of the syphon action between F and E. The valve H then

closes, and the valve A is forced open, when the action just described is

repeated. This ram is made double-acting by putting two rams side by

^^/^hn7??;fiT)."Ki7?T^7.7^

Fig. 267. —Lemichel's Hydraulic Syphou Earn.

side, and connecting the valves A by a beam, so that one goes down when the other goes up. Syphon rams have been constructed in which the ram is above the source of supply, as in fig. 267.

The ram is at A, the momentum valve at B, the non-return valve at C, and the discharge at D. Water is syphoned from E to F, and part is delivered by the action of the ram at D. To ensure the continued action

of the ram, it is necessary that the syphon shall be kept free from an accumulation of air, and the inventor, Lemichel, accomplishes this by providing an outlet air-valve at H, and a flexible diaphragm in the pipe

at I. The result is that the reaction in the pipe K, after the closing of the momentum valve, expels the air through the valve H. Pearsall's Hydraulic Kam.—Large rams have been made with momentum valves operated, not by the flow of the water in the supply HYDRAULIC RAMS, PUMPING MAINS, ETC. 315

pipe, but by independent means. Pearsall's ram is of that class. It is

made to pump a larger quantity of air than that required to keep the air- vessel charged, and the surplus air is used to work a small air engine

Fig. 268. — Section of Pearsall's Hydraulic Kam for forcing water. which operates a large equilibrium momentum valve, quietly without the hammering action of the ordinary momentum valve.

This ram is shown in fig. 268. A is the flow-pipe (of a certain length depending on the fall and other circumstances of the case) conducting —

3i6 PUMPING MACHINERY. water from the source to the tail-race B. C is the main valve, opening and closing communication with the tail-race. D D are delivery valves opening into the air-vessel E. F is the delivery pipe. The main valve is opened and shut by means of a small motor G, worked by the com- pressed air from the air-vessel. H is an air-valve carrying a float J, the distance of which from H is adjustable by means of a screw K and rod L.

The action is as follows :

The flow-pipe being full of water, the main valve is opened by the motor, and water flows into the tail-race, thus putting into motion all the water in the flow-pipe, the chamber M also emptying itself into the tail- race and being filled with air through the valve H. After the flow has continued for a certain time —say, for example.

l>W:{^^^M^Ai^)f^vv?)^

^zti

Fia. 269. Hydraulic Ram in which the water used as motive power is made to pump other water.

a cylinder ; d, a plunger e, the a, is the momentum valve ; 6, a piston in pump ; the the suction pipe for clean water. suction, and /, the delivery valve of pump ; g, There are many other ways, sufficiently ohvious, of applying hydraulic rams for this purpose. two seconds—the main valve is closed by the motor. During the closing of the valve the flow of the water is not checked, as it can rise without resistance in the chamber M, the air freely esca|^ing by the valve H. The motion of the valve C need not, therefore, be rapid. When the main valve is closed and the water has reached a certain height in the chamber, it raises the float J, and closes the air-valve H. If the float be adjus'i^d so as to close the air-valve, while there is still some air in the chamber, thih air is then compressed (by the energy of the column of water) till its pressure equals that in the air-vessel, when it and some of the water is forced into the air-vessel. Water thus continues to flow into the air-vessel until the energy of the column of water in motion is exhausted by the resistance in the air-vessel, when the column of water — ) —

HYDRAULIC RAMS, PUMPING MAINS, ETC. 317 comes to rest, and the delivery valves gently close. The action of the motor is timed, so that after this has taken place the main valve is again opened, and the cycle of operations is repeated. Of course water flows out of the air-vessel continuously under pressure through the delivery pipe F.

It is not necessary, ordinarily, to confine and compress more than a very small quantity of air in the chamber.

If the small quantity necessary to supply the motor be confined, it will suffice for all the cushioning that is desirable. In starting the machine, however, it is an advantage to adjust the float so as to force in a considerable quantity of air, to fill the air-vessel with compressed air, and reduce the water level to a height of a few inches only above the valves, at which height it can easily be kept, thus avoiding the in- convenience arising from a mass of water above the valves, and thus utilizing the full capacity of the air-vessel. Hydraulic rams supplied with impure water are used for raising clean water, the source of each kind of water being distinct. The power may be applied to a piston actuating the piston of a pump. A very obvious arrangement is that shown in fig. 269.

The Taylor Hydraulic Air Compressor is described by the inventor in the following terms.

Fig. 270 shows a complete compressor ; its details are as follows :

A. Penstock or water supply pipe. B. Receiving tank for water. C. Compressing pipe. D. Air chamber and separating tank.

E. Shaft or well for return water. (The required pressure is proportional to the depth of the water in this shaft. F. Tail-race for discharge water. 6. Timbering to support earth. H. Blow-off pipe.

I. Compressed air main.

J. Headpiece, consisting of a. Telescoping pipe with

b. Bell-mouth casting opening upwards.

c. Cylindrical and conoidal casting.

d. Vertical air supply pipes. (Each pipe has at its lower end a number of smaller air inlet pipes branching from it towards the centre of the com- pressing pipe.)

e. Adjusting screws for varying the area of water inlet. /. Hand-wheel and screw for raising the whole headpiece. K. Disperser. L. Apron. M. Pipes to allow of the escape of air from beneath apron and disperser. N. Legs by which the separating tank is raised above the bottom of the shaft to allow of egress of water. P. Automatic regulating valve.

The water is conveyed to the tank B through the penstock A, —

3i8 PUMPING MACHINERY.

where it rises to the same level as the source of supply. In order to start the compressor, the headpiece J must he lowered by m.eans of the hand-wheel / so that the water may be admitted between the two

castings b and c. The supply of water to the compressor, and consequently

Fig. 270. Fig. 271.

Figs. 270 and 271. —ApparaUis for compressing air by means of a fall of watei- Taylor's system. the quantity of compressed air obtained, is governed by the depth to which the headpiece is lowered into the water. The water enters the compressing pipe between the two castings b and c, passing among, and in the same direction as, the small air-inlet pipes. A partial vacuum is created by the water at the ends of these small pipes, and hence atmos- HYDRAULIC RAMS, PUMPING MAINS, ETC. 319

pheric pressure drives the air into the water in innumerable small bubbles, which are carried by the water down the compressing pipe C. During their downward course with the water the bubbles are compressed, the final pressure being proportional to the column of return water sustained in the shaft E and tail-race F. Fig. 271 shows the relative

size of the bubbles as they descend in a compressing pipe, 116 ft. in length. When they reach the disperser K their direction of motion

is changed, along with that of the water, from the vertical to the horizontal. The disperser directs the mixed water and air towards the

circumference of the separating tank D. Its direction is again changed towards the centre by the apron L. From thence the water flows outward,

and, free of air, passes under the lower edge of the separating tank.

During this process of travel in the separating tank, which is slow

compared with the motion in the compressing pipe C, the air, by its buoyancy, has been rising through the water and pipes M M from

under the apron and disperser to the top of the air chamber D, where it

displaces the water. The air in the chamber is kept under a nearly uniform pressure by the weight of the return water in the shaft and tail-race.

The air is conveyed through the main I up the shaft to the automatic regulating valve (of which a diagram is given), and from thence to the engines, etc. The air pressure in the main and air chamber increases 1 lb. per sq. in. for each 2 ft. 3J in. that the water is displaced downwards in the air chamber by the accumulating air. The variation in pressure from this source will not be more than 3 lbs. per sq. in. in a working plant. As the automatic valve requires a change of only 1 lb. per sq. in. pressure to close it completely, it will be evident that by properly adjusting the valve some air can always be retained in the air chamber, and that the water can be prevented from ever reaching the inlet to the air main.

If a large quantity of air has accumulated in the chamber, the valve allows of its free passage along the main, but when the air is being used more quickly than it is accumulating, and the pressure decreases below a certain point, because the chamber is nearly emptied of air, the valve shuts partially or completely, adjusting itself to the supply from the compressor. When the air has displaced the water almost to the lower end of the compressing pipe, it escapes through the blow-off pipe H. Syphons. —A syphon-pipe is a pipe used to convey water from one level to a lower level over an intervening higher level automatically, thus avoiding tunnelling or excavating.

Let A., fig. 272, be a hill over which water is to be taken from reservoir h to reservoir c, and let the height d be less than that of a column of water at atmospheric pressure ; then, if the ends of the pipe be submerged, and the air be exhausted from the pipe at e, the pipe will become filled with 320 PUMPING MACHINERY. water. As the pressure of the water column e c is greater than that of the water-column e b, water will descend from e. to c, and ascend from 6 to e, under atmospheric pressure, and a stream will be set up from b to c. To maintain this stream it is necessary that no air shall be allowed to collect in the pipe. Air collecting at e would destroy the action by reducing the effective atmospheric pressure sustaining the column of water in the shorter

Fig. 272.—Ordinary Syphon Pipe. leg of the syphon e h. To exhaust the air from the syphon, and to prevent its subsequent accumulation therein, an air pump is fixed at e and worked as occasion requires.

The accumulation of air is guarded against in various ways.

Let the longer leg of the syphon c, fig. 273, be at a small angle with the horizon, then a moderate velocity of water through the pipe will be e

Fiu. 273. ^Syphon in which air will not collect, but is entrapped with the water and discharged, ^ sufficient to catch up and carry with it the air which otherwise would collect at e. It constantly occurs in engineering practice that special cases have to be dealt with. The following is an interesting case met with in the author's experience.

A pumping main was to connect a reservoir on one side of a hill with a reservoir on the other without tunnelling, and the water was to be pumped through during the day only. A syphon arrangement would HYDKAULIC RAMS, PUMPING MAINS, ETC. 321

meet the requirements, provided air could be prevented from accumulating at its apex during the cessation of pumping. This apex was too far away from the pumping station to allow of an apparatus requiring personal attention being placed there, therefore an automatic control of the syphon

action had to be devised. In fig. 274 d is the pumping station, e a stand

'-^y^

Fig. 274. —Pumping Main over a hill aotino; as a syphon in reducing the pumping head

pipe on the apex of the syphon, c the discharge end of the pipe. An an

valve is placed in the stand pipe e, and a weighted valve at c. When the

main was charged, the air escaped from e, and water rose in the stand pipe.

The pressure thus produced lifted the valve at c, and the sy|:ihon action was

started. The water flowed into a bucket, which, when full, further raised

Fig. 276. —Hydraulic Main crossing a valley, usually t 'vmed an inverted syphon,

the flow being from a to h.

the valve at c by means of the lever, and kept it fully open. When pump- ing ceased the water in the bucket escaped by a small hole in the bottom, and tlie weight on the valve caused it to close again while the syphon was

still filled with water.

Inverted Syphons so-called are pipes carried across valleys, as in fig. 275, and are merely depressions in the pipe. They present no special features or difficulties in themselves, but special applications often require special provisions. If the syphon is a long one of such a capacity as to

involve a risk of flooding from its bursting, a valve should be placed at a, 21 32 2 PUMPING MACHINERY. which will close the pipe automatically directly the velocity of the water is increased by the bursting of the pipe. This may involve an overflow into a water-course at a to take away the water when the pipe is closed. Sjrphons have been used to drain fen lands. Mr. Wheeler, in his book on the Drainage of Fens, thus describes the Middle Level syphons. " When an accident occurred to the Middle Level sluice on the river Ouse, in 1862, it became necessary to place a solid dam of a very substantial character across the drain ; and in order to afford means of discharging the water from the drain into the river, syphons were erected under the direction of Sir John Hawkshaw. " The syphons erected at the Middle Level were sixteen in number, laid across the dam at an inclination of 2 to I on either side, each end terminated by a horizontal length containing the upper and lower valves.

"The upper surface of the lower pipes was laid 1 ft. 6 in. below low

water of spring tides, and the top of the syphon was 20 ft. above the same level. The syphons were of cast iron, \\ in. thick, 150 ft. in total length, and 3 ft. 6 in. in diameter. They were put into action by exhausting the air from the inside by an air pump worked by a 10 horse-power steam engine. These syphons continued in use fifteen years. Owing to their capacity not being sufficient to cope with heavy floods, and to discharge the water with sufficient rapidity, there was frequently a difference of more than 4 ft. between the level of the water in the drain and that in the river, the average varying from 2 to 3 ft., a very serious loss in such a flat district. It being found that the cost of adding a sufficient number of syphons to drain the fens effectually would be greater than that of building a new sluice. Sir J. Hawkshaw reluctantly advised the latter course, although contending that the syphons were right in principle."

The discharge of a syphon running full and free from air is that of a pipe of the size and length of the syphon with a head of water equal to the difference in level between the inlet and the outlet. Valves, bends and other obstructions must, of course, be taken into account and allowed for. HydrauKc Mains. —When water is at rest in a main or pipe the pressure on the sides of the pipe is that due to the head of water above that particular part regardless of the cross section of the pipe, but when the

water is in motion that is not the case, and the lateral pressure on the pipe will be influenced by the altered condition.

Assume that a main is under pressure from a service reservoir.

With the water at rest, the pressure is that due to tlie head of water above the pipe, but when the water is in motion part of the pressure head is changed into velocity head, and the lateral pressure on the side of the pipe becomes less ; but if the velocity be suddenly checked the pressure becomes more, because the vis viva of the water is spent in creating an additional head or pressure. The flow of water in a pipe of varying capacity is illustrated in the following figure (276). Let the water be flowing from the reservoir a to the reservoir b through HYDRAULIC RAMS, PUMPING MAINS, ETC. 323 a pipe of varying capacity. The difference in the levels of the water in a and h, together with the friction through the pipe, will determine the rate of delivery; but as the pipe has a varying cross section the water will move in different parts of the pipe with dififerent velocities. In the narrow parts it will move quickly and in the wide parts slowly, but in all parts of the pipe (neglecting friction) the sum of the pressure and the velocity heads will be the same. If vertical pipes be inserted in the sides of the pipe at points of different cross section, as shown in fig. 276, then the pressure head at those points will be indicated by the height of the water column in the vertical pipes.

Neglecting friction, the total head is h and the velocity head is li^.

Where the pipe is very much enlarged then the pressure head is nearly the full head, and the velocity head is very small. (It is on this principle that the Venture water meter is constructed.)

If a stop valve be placed in the pipe close to &, when closed the water

CL 324 PUMPING MACHINERY. reaction will then take place, and the water will then flow backward into the air-vessel, and the reciprocating action will continue till the vis viva of the water has been absorbed in friction. With a long length of main and a high velocity of water the reaction on the air-vessel may be dangerous.

Assume the main to have a capacity of 5 gallons, or 50 lbs. per ft., with a length of 5000 ft., the velocity of the water being 3 ft. per second, then the energy of the water will be 5000x50x9 ? = 35,000ft. lbs. 64

The area of the pipe in section would be 450 sq. ins.

35000^-- 450

Therefore if a piston of the same area as the pipe were made to act as

=Q

Fig. 277. —Hyih-aulic Air Compressor. a buffer to absorb all the energy, it would require a mean resistance of nearly 78 lbs. per sq. in. and a movement of 1 ft. In these calculations the friction of the water in the pipe has been

neglected ; but it is readily seen that in pumping into long lengths of main, care should be taken to start and stop the engines slowly. Relief valves are used to avoid accidents.

Assume that there is no air vessel, but a retaining valve in its place, and that the supply through the retaining valve is suddenly stopped ; then the reaction would produce a great shock, the water reacting on the valve with the effect of the ' water hammer.' Hydraulic Air Compressor.—Fig. 277 represents a hydraulic air com- pressor designed by the author, in which a column of water of considerable height is used to compress the air, and in which the principle of the hydraulic ram is more or less brought into action. Referring to the figure, G is the pipe bringing the water from an —

HYDRAULIC RAMS, PUMPING MAINS, ETC. 325

described and elevated reservoir, B is a valve bos having valves of the type illustrated in detail in Chap. XII., fig. 212. subsidiary valve D, and C is a float for the purpose of actuating the purpose of admitting water under pressure from the column G for the and de- working the main valve in B. Air is compressed in the vessel A the livered into the receiver E through a non-return valve not shown m

illustration. The mode of operation is as follows : the valve Water from the pipe G is admitted into the vessel A through resistance in the in B. The water rushing into the vessel A meets with a begin with, the compression of the air, but as the resistance is small to which is water in the pipe G acquires a velocity, and therefore momentum the receiver utilized in the final compression of the air and its delivery into is pushed up. E. The water level in A having risen to the float C, the float

construction of the Fig. 278. Hydraulic Air Compressor used during the Mont Cenis Tunnel.

thereby reversing the position of the subsidiary valve D. The inlet valve water in then runs out in B then closes, and the exhaust opens. The A by o-ravity, drawing in air from the atmosphere through suction valves not shown in the illustration, and the action is repeated. It will be seen that the momentum of the water for the final compression will depend on the length of the pipe G and the velocity the water in it acquires during the compression. for letting off any water which enters F is an automatic drain valve the receiver E. Sommeiller Hydraulic Air Compressor. —The early compressors used at the Mont Cenis tunnel were constructed by the Cockerill Company at Seraing, to the designs of M. Sommeiller. The chamber K, fig. 278, having been filled with air at atmospheric pressure, the valve A is opened and 326 PUMPING MACHINERY. high-pressure water admitted at the bottom, thus compressing the air above it as it fills the chamber. As soon as the pressure of air in the chamber exceeds that in the mains, the outlet valves C are forced open, and the air is delivered to the receiver. The exhaust valve B is then opened, and as the water level falls in the chamber K, air is sucked in through the inlet valves at d. The pressure at which the air is delivered depends on the head of water available. At the Mont Cenis installation, the head of water was 85 ft. and the air pressure 75 lbs. per sq. in. It made about three strokes per minute. In many respects this compressor gave good

Fig. 279.— Fohle's Air-Lift Pump. results, but it was very bulky for the quantity of^air delivered and the efficiency was low.

Pohle's Air Lift Pump.—In tig. 279, C is a water column extending some distance below the water level in a well or cistern. A pipe conveying com- pressed air is taken down to the bottom of the column and air is injected into the water in the column in an upward direction. The air mixing with the water forms air bubbles, and thus reduces the specific gravity of the water column, and the water in consequence rises higher in the pipe than the level of the water outside. It will readily be seen that the lift must not be very great compared with the submersion. —

HYDRAULIC RAMS, PUMPING MAINS, ETC. 327

It therefore becomes necessary to use the arrangement of double lifts, as shown at A and B, when the height to which the water has to be raised is considerable. Mr. H. C. Behr and Mr. Kendall in America made some experiments with this pump to ascertain its efficiency. The general results are given in the following table :

Submersion of the column in ft., 52

Height to which the water was raised, ft., Percentage of efficiency.

The best efficiency was obtained when the pressure of the air did not greatly exceed that due to the submerged column and the height to which the water was lifted did not much exceed the submersion. The authors say, " That the efficiency in their trials did not take into account the efficiency of the air compressor. Therefore if that is taken as 70 per cent., then the total efficiencies in the above tables would be only 70 per cent, of the amounts given." It will readily be seen that the system is one of low efficiency. , , ,

IKDEX.

A. D. LEAD mine water pressure engines, Birniingliam pumping-engines, compound 229-234. Cornish, 269.

Accumulator, Armstrong, 178. ,, pumping-engines, Whitacre, steam, 181, 182, 188. 46. charger, Air Wippermann, 74. ,, water supply, Aston pump-

,, corapiossor, hydraulic, Davey, 324. ing station, Plate I. and

, , S o m e i 1 1 e r, p. 45. , m

325. ,, water sui)ply pumping-

,, Taylor,317-319. engines, 258, 262, 263.

,, in pum[)S, 83. ,, water supply, variation in

,, leaks in stuffing boxes, 92, 121. consumption, 246.

,, lift pump, Pohle, 326. Black, Dr., latent heat of steam, 14.

,, pump and condeu.ser, Cornish engine, Boiler pressure, influence on economy of 92. steam, 32, 33, 34, 35.

,, ,, ,, ,, differential en- Boilers, Cornish, 101. gine, 121, 122. Trevithiok, 23.

,, ,, double-acting, 121. ,, ^Voolf, cast iron, 23.

,, ,, valves of, G9. Bore-hole pumps, 267, 272

,, vessels, capacity of, 70. ,, water, level indicator, 271.

,, ,, function of, 324. ,, wells, 261.

,, ,, " mode" of charging, 73, 74. ,, ,, at Widnes, 266, 267.

,, on hydraulic engines and hy- ,, ,, cost of, 271.

draulic mains, 239. ,, ,, Davey's system, 265. American compound rotative, 106, 107. Boulton & Watt engine, Birmingham

,, geared engine, 107, 108. waterworks, 48, 49.

, , triple expansion engine, 268, 272. ,, ,, engine, diagram Irom, Appold centrifugal pump, 307, 308, 309. 49.

Armstrong hydraulic system, 178. ,, ,, engines, duty of, 20. Arsimont, pumping engines at, 134. ,, ,, ,, in Cornwall, Ashley well ]>ump, 57. 20-25.

Aston pum]ping station, Plate I. and p. 45. ,, ,, first engine in Corn- Atmospheric engines, 13. wall, 17.

Automatic gear, atmospheric engine, 7. ,, ,, iiartnership, 15.

,, ,, pumping-engines, Beigh- ,, ,, patent expired, 20. 11. ton, 7, 8, ,, , pumping-engines.

,, ,, Savery's engine, 7. Frontispiece, Chap. • I., and p. 13.

Bailing tanks, 155-158. ,, ,, waterworks engine, 42. Galloway's, 156, 157. Branca steam-engine, 1. Balance valve for pumfjing mains, 74, 244. Bridges, geared engine, 108, 109. Balancing or shutter valve, 210, 212, 213. Brine, water pressure engine for pumping, Barclay's Grass opper engine, 117. 226-229. Basset mines compound Cornish engine, Bryan pumping-engine, Lea Bridge, 285. 95. Bucket pumps, 51, 145, 151-154. Beighton automatic gear for atmospheric Bull Cornish engine, 91. engine, 7, 8, 11. Buoy employed to make engine auto- Birmingham Canal. Watt's engine, Frontis- matic, 7. piece, Chapter I., p. 13. Burnt Fen, centrifugal pumps at, 303- Birmingham hydraulic power supply, 296. 307.

,, pumping-engines, Boulton Bushel of coal, weight of, 13, 26. and Watt, 48, 49. Butterfly valves, 17, 56. 328 INDEX. 329

Cables, mode of supporting electric, 196, Compound engines, non-rotative, Cam- 199. bridge sewage Calumet and Hecla mine, pumping-engine works, 269, 272.

at, 106-108, 116-117. ,, non-rotative, Widnes Cam gear, 214, 216. waterworks, 266, Cambridge sewage works pumping-engino, 270.

269, 272. ,, rotative, American, Cameron sinking-pump, 162. 106, 107.

Capstan engine, 148. ,, rotative, Calumet and Cataract gear, Cornish 205. Heola mine, 116.

„ D,Lvey's, 205, 208. ,, rotative, Copenhagen

, , , , water pressure, 208. waterworks, 293.

,, pausing, 205, 209. ,, rotative, Shanghai Centrifugal pumps, 301-311. waterworks, 261.

„ Appold, 307. ,, rotative, Southwark at Burnt Fen, 303-307. and Vauxliall Water

,, ,, at Leith Docks, 306, Co., Hampton, 290.

307. ,, rotative beam, Lei-

,, ,, driven by Pel ton cester sewage works, wheel, 303, 305. 249.

,, ,, effect of roughness of ,, rotative beam, London water passages, 309. waterworks, 245, high lift, 195-199. 248.

,, onion bearing for, 305, ,, ,, steam pump, Birming- 306. ham waterworks,

,, Parson's experiments, 259, 262. 307. Copenhagen waterworks pumping-engine,

,, Rankine, 308. 293, 294.

,, ,, Thompson's experi- Corliss valve gear, 29. ments, 307. Cornish bull engine, 91.

,, ,, velocity of, 302. ,, cataract gear, 205.

,, ,, Webber's experiments, ,, cycle engines, 45, 48.

308, 310. ,, ,, engines, air pump, and con- Coal, consumption of, atmospheric engines, denser, 92.

16, 19. ,, ,, engines, construction of, 88.

,, ,, compound Cornish, ,, ,, engines, distribution of 94. steam, 44.

,, ,, Cornish engines, 19, ,, ,, engines, duty of, 93.

20-26. ,, ,, engines, duty reports, 98-101.

,, ,, duty reports, 13, 16, ,, ,, engines, expansive working, 19-26, 98, 100, 78.

101. ,, ,, engines, feed water heaters,

,, ,, Grose's Cornish 98.

engine, 24. ,, ,, engines for mining purposes,

,, ,, Savery's engines, 16. 77, 89.

,, ,, Smeaton'sengines, 17. ,, ,, engines, formula for weight tableof duty, 101. and velocity of moving

,, ,, Taylor's engine, 25. parts, 81. engines, ,, ,, Watt's 11, „ ,, engines, general principles, 19, 20. 75.

,, ,, West's engine, 25. ,, ,, engines, indicator, diagrams weight of busliel, 13, 23. of, 76.

Compound engines, Cornish, semiportable, ,, ,, engines, limit of boiler 118. pressure, 78. Cornish, Birmingham ,, ,, „ ,, engines, limit of expansion, waterworks, 259, 78.

263. ,, ,, engines, maximum strains, double-acting. differ- ,, ,, 79, 80. ential, 115. ,, ,, engines, principles of double-acting, placed ,, ,, economy, 78.

over shalt, 110, ,, ,, engines, simple and com- 111-115. pound. Chapter V., 88.

,, ,, hydraulic power trans- ,, engine, compound, 78. mission, 180, 182. „ ,, compound. Basset mines,

,, ,, non-rotative, Bir- 95, 97.

mingham water- ,, „ compound, Birmingham works, 258. waterworks, 263. 330 INDEX.

Cornish engine, compound, Hornblower, Differential engine, pump rods, set-off for 26. sinking lifts, 126.

,, ,, compound, semi-portable, ,, ,, pumps, working on 116, 118. air, 82.

compound, Sims, 24, 26. ,, „ sinking lifts, 122, 123, compound, Trevithick, 23. 124, 125.

compound, Waihi, 97, ,, ,, sinking lifts, lowering 109, 110. screws, 127.

compound, with parallel ,, ,, velocity of, 82. motion beams, 96. valve gear, 205, 206, 208, 209. compound, Woolf, 22. Dip workings, drainage of, 128, 222.

single cylinder, 88. ,, ,, hydraulic engine, 224, 225. speed of piston, 76. Displacement diagram for double-acting steam cushioning, 69. pumps, 71.

,, cylinder, 92. ,, ,, for single-acting

,, nozzles and valves. pumps, 71.

90. ,, ,, for three-throw table of comparison, 80. pumps, 72, 73.

,, of equivalent duty, Distributing mains, balance valves for, 244.

101. ,, ,, pumping into, 244. town water supply, 48, 49, Double beat pump valves, 63, 66, 152. 245, 247, 269. Drainage of dip workings, 128, 222, 224.

velocity diagram, 77. ,, of fens, centrifugal pumps for,

,, indicator, use of, 303-306.

77. ,, ,, piston pumps for, 301, waterway through pump 311.

valves, 76. ,, ,, scoop wheels for, 298- weight of pitwork, 77. 300.

Wolverhampton water- ,, ,, syphons for, 322. works, 245, 247. Duplex hydraulic pumps, 191, 240.

,, pitwork, 144. ,, valve gear, 213, 215.

, , sinking lift, 145. Duty of Cornish engines, 20-26, 92.

,, valve gear, 203-205. ,, Savory's engines, 16.

Cushioning valves, 209. ,, Smeatou's engines, 17.

Cut-off gear, differential, 209. ,, Watt's engines, 19, 20.

,, valve, Meyer's, 210. ,, table of, 101. Duty Reports, 22, 98, 99, 100.

Damming water in shaft, 170. ,, „ Fowey Consols engine, in- Davey cataract gear, 205-208. accurate, 25.

,, compensating device (pumping), 86. Early history of pumpiug-engines.

,, compound Cornish engine, Basset Chapter I. mines, 95, 97. East London waterworks triple expansion

,, compound Cornish engine, Waihi engines, 257, 260, 283, 285. mines, 97, 109, 110, 135, 141. Eccentric motion, 217.

, , differential valve gear, 206. Economy, limit of boiler pressure, 25, 26.

,, differential valve gear with cut-off Efficiency curves, steam, 35.

, of and trip motion, 206. , electrical high lift centrifugal

,, empirical formula (steam), 33. pump, 195.

,, hydraulic air compressor, 304. , , ratio, definition of, 35.

,, ,, power system, 178. ,, ,, of condensing engines,

,, shutter valve, 210, 212, 213. table of, 42.

Differential engine, air pump of, 121. II 11 of non-condensing en-

,, ,, as apjjlied under- gines, table of, 42.

ground, 84. ,, ,, practical use of, 36.

,, ,, bucket pumps, slung ,, ,, table of, 37. in shaft, 123-125. Electric power transmission. Chapter compound, 80. X., 194. Electrical ,, example of high lift centrifugal pumps, large pumping efficiency of, 195. plant, 118-134. Electrical high lift centrifugal pumps, condenser of, 122. description of, at Horcajo mines, 195- indicator diagrams 199. from, 83. Electrically driven plunger pump, 199- plunger pumps, 123- 202. 125. Ellington, losses due to working con- pump rods, 122, 127. ditions of pumping-engines, 294. , .

INDEX. 331

Emerson, description of Newcomen's steam Hydraulic air compressor, Sommeiller's, engine, 8. 325. dip work- Energy of motion, formula for, 75. ,, engine, for draining Expansion gear, cam, 214, 216. ings, 224. 222-226. ,, Corliss, 211, 213. ,, Griff colliery, power pipe, ,, „ Cornish, 203, 204, 205. ,, size of

,, ,, dlrterential, 206-209. 192.

,, Meyer, 210, 213. mains, flow of water in, 323.

,, shocks in, 322, 324. Feed water heater, compound Cornish pilot pumps, 193. engine, 98. plant, at Pluto colliery, 192. engine ,, ,, ,, Cornish cycle en- power, modern power gine, 49. with steam accumulator, 188,

,, ,, ,, equilibrium steam, 189, 192. 48. Power Co. 's pumping-engine, Filter pumps, 243, 303, 305. trial of, 286, 287. Fishing tackle, pump valves, 69, 70. power supply, Birmingham, Flooded colliery bailing tanks, 155-157. 296. transmission, Chapter ,, ,, plant for unwatering, power 166-173. IX., 174. application ,, ,, sinking lifts, 170. power transmission,

,, ,, suspending pumps, 169. in Westphalia, 192.

, unwatering of, 166. power transmission, Arm- , , Francois automatic gear for Savery engine, strong's system, 178. 7. power transmission, Davey's system, 178, 191. Galloway bailing tanks, 156, 157. power transmission, explana- Gas engines for pumping, 296. tion of principle, 174. Geared puraping-engines, American, 107- power transmission, high 109. pressure system, 187. Governing engines, cataract gears, 206, power transmission, Marseilles, 208, 211. 182. gear, 211, transmission, Marseilles, ,, ,, Corliss power 212, 214. description of, 182. gear, transmission, Marseilles, ,, ,, differential power 206-208. results of working, 183-187. Grasshopper pumping-engine, Barclay's, power ti'ansraission, Marseilles, 117. cost of machinery, 186. Gribble compound Cornish engine, 23, 24. power transmission, Marseilles, Griff colliery hydraulic pumping-engine, efliciency of machinery, 183. 222-226. power transmission power Grose improved Cornish engine, Wheal engine, 177, 183. Hope, 24. power transmission steam ac- Grose improved Cornish engine. Wheal cumulator, 178, 181, 188. Towan, 24. power transmission, water rod system, 175. Halfwbg, scoop wheel at, 298. power transmission, water rod Hampton pumping-engine, trial of, 290. system, at Devon Great Con- Hawkshaw, Middle Level syphons, 322. sols, 194.

Hero steam engine, 1 power transmission, water rod Horcajo mines, electrical high lift centri- system, application at fugal pump system, 195-199. Saarbrucken, 175-178. Horizontal pump rods, 148. power transmission, water rod Hornblower compound Cornish engine, system, results of working, 12, 18, 26. 177. in Cornwall, duplex, ,, introiluotion pumps, 191, 240.

12, 18. ,, energy of water in Hugo mine underground pumping-engine, motion, 193.

130-133. ,, shocks in, 192.

Husband's valve, 66. ,, underground, 179. Hutton Henry colliery water pressure ram, Leblanc's, syphon, 313.

engine, 234, 235. ,, Leraichel's, syphon, 314.

Hydraulic air compressor, Mont Cenis ,, Pearsall's, 314, 315.

tunnel, 325. ,, simple, construction of, Taylor's, 317- ,, ,, compressor, 312, 313.

319. ,, special, 316. Davey's, „ ,, compressor, 324. rams. Chapter ,XVI., 312. ,, ,,

332 INDEX.

Inclined shaft, 148-150. Mining engines, Barclay's grasshopper, 148-150. „ ,, pitwork, 117. plunger pumps, 150. 94- ,, ,, , , compound Cornish, Inertia of pump rods, water pressure 98, 109-111, 118.

engines, 238, 239. ,, ,, compound, double-act-

,, ,, water column, effect of, 84, ing, 112.

85. ,, ,, compound, inverted, Inverted syphon, 321. 113.

,, ,, difl'erential engines, 84, Kibble, 156. 115, 120.

Klein pumps driven by electricity, 199- ,, ,, electric, 102. 202. flywheel, 102.

Kley mining engine, 104-106. ,, ,, hydraulic, 102. Kley's, 104.

Latent heat of steam. Dr. Black, 14. ,, „ ,, cost of, 106.

Lea Bridge pumping-engine, 285. ,, ,, Regnier's, 103.

Lean historical statement, 21. ,, ,, rotative, 103.

,, improvement of pitwork, 21. ,, ,, ,, American, 106,

,, monthly duty records, 22. 107.

Leavitt triple expansion engine, 264. ,, ,, types of. Chapter VI., Leblanc syphon hydraulic ram, 313. 102.

Leeds waterworks pumping-engine, 250- ,, ,, underground, 126-135. underground, high lift, 257. , , Leicester sewage works compound beam 134.

engine, 249. ,, ,, underground, condensa- Lemichel syphon hydraulic ram, 314. tion in steam pipe, Liverpool waterworks pumping-engine, 126.

trial of, 288. ,, ,, valves and nozzles of, Load factor of pumping-engines, 295. 113. Load and speed, influence of, on engine Mont Cenis tunnel hydraulic air com- economy, 296. pressor, 325. London waterworks pumping-engine, 248. Motion, energy of, formula for, 76. Losses due to working conditions of pump- Miike mines, pump rods, 132. ing-engines, 294. Losses of steam engines, 27, 28, 30. Newcomen and Cawley atmospheric Low lift bucket pumps, 301. engine, 5. engine, 12. ,, ,, piston pumps, 301. Newcomen 5, Beighton's automatic ,, pumps. Chapter XV., 298. ,, ,, valve gear, 7, 8.

Maik steam engine trials, 43. ,, ,, description, 8.

Man engine, 148. ,, injection in cylinder, Mansfield salt mine water pressure engine, 7.

227-228 ,, ,, model of, Glasgow Marseilles hydraulic power plant, 182. University, 14.

,, hydraulic power T)lant, cost of Non-rotative pumping-engines, general machinery, 186. principles of. Chapter IV., 75. hydraulic power plant, descrip- Odessa pumping engine, 280. tion of, 182. hydraulic power plant, efliciency Parallel motion beams for pumping- of machinery, 183. engines, 96, 110, 115, 257, 259.

,, hydraulic power plant, results Parson's experiments with centrifugal of working, 184-186. pumps, 307, 309. Meyer cut-off valve, 210. Pausing cataract 205, 209. valves, 216. Peai-sall hydraulic ram, 314, 315. ,, ,, expansion Middle Level syphons, 322. Pelton wheel used fur driving centrifugal Mining engines, American, with spur pump, 244, 303, 305.

gearing, 107, 108. ,, ,, used for lowering pumps, American, with spur- 129. ,, ,, gearing and equal- Perfect steam engine, consumption of steam izing device, 108. in, 33.

at Calumet and Hecla ,, deflnition of, 27. , ,, ,, ,, mine, 106-108, 110, Pipe rods, 147.

116. ,, ,, of varying section, flow of water Idria, Kley's systrm, in, 323. ,, ,, at result of working, Pit head frame, 119, 169. 104-106. Pitwork, Chapter VII., 142. 106. Cornish, 144. ,, ,, at Michigan, ,, , ,

INDEX. 333

Pitwork for inclined shaft, 147, 150. Pumps centrifugal, velocity of, 302.

, experiments, Pluto colliery, description of hydraulic , Webber, plant, 192. 308, 310. Pohle air lift pump, 326. „ with Pelton wheel, efficiency of, 327. 244, 303, 305. „ ,, ,, „ Potter, Humphrey, 7. Cornish, plunger, 138, 139. Progress of economy in pumping-engines, displacement of, 70-72. 25, 26. displacement diagrams, 71, 72, Pulsometer, 163. 73. Pump column, inertia of, 64. duplex, hydraulic, 191, 193.

,, rods, 142. for pumping sewage, 56. lift force, 61. ,, ,, catch pieces and banging and beams, 132. lowering into well, 270, 274. forming rising main, 147. piston, 54.

horizontal, 148. ,, and plunger, 54. iron and steel, 142, 143. for low lifts, 301. method of staying, 132, 147. plunger, arrangement of, 122-125, timber, 142. 130, 131, 199.

, description of, 52. vibration of, 145. ,

weight of, 142. , double-acting, 55. ,

wrought iron, 142. ,, electrically driven, 199- Lves, air pump, 69. 201.

butterfly, 17, 56. ,, for inclined shaft, 150.

double beat, 66, 152. ,, packing of, 53.

fishing tackle fordrawing, 70. ,, working on air, 82-85. hat band, 69. Pohle, air lift, 326, 327. husband, four-beat, 66. practical difficulties in working, multiple ring type, 66. 56. taper seatings, 154. Reidler, mechanically moved Teague, 56. valves, 59, 61. quick reciprocating, types of, 64, 65. , Pumping by hand, cost of, 5. 62. quick reciprocating, ,, engines, development in Corn- ,, wall, 20-26. details of, 63. quick reciprocating main, motion of water in, 324. ,

,, retaining valves in, 324. suction valve, 63. well, ,, syphon, 321. Restler, 59.

mains. Chapter XVI. , 312. riding column in, description of, shaft, plan of, 130. 52. Pumps, Ashley well, 57-59. Rittinger, 133. sinking, air in, 150-154. ,, and pump valves, Chapter III. , 51. 63, lowering of, ,, bucket, 51, 145. ,, 128, 129. and plunger, description speed of, 68. , ,, of, 53. tliree-throw, bucket, 55.

illustration ,, without foot , , ,, ,, of, 53, 54. valves, 55.

,, double-acting, without ,, plunger, 55. foot valves, 58. types of, 51. „ for low lifts, 301. undergi-ound, hydraulic, 178, 179, centrifugal, 301-311. 191,193. affected by roughness well, without foot valves, 67. ,, ,, of water passages, 307. Rankine centrifugal pump, 308.

Appold, 307, 308, 309. ,, formula, 31, 32. Fen, 303- Rateau, pump system at Horcajo, 195- Ij at Burnt 307. 199.

., at Horcajo mine, 195- Receiver engine, 45. 199. Regnier raining engine, 103, 104.

,, at Leith Docks, 306, Reidler pump, 59, 61-63. 307. Restler, pumping-engine, Hampton, 291.

,, onion bearing for, 305, ,, well pump, 59-60. 306. Retaining valves in pumping mains,

,, Parson, experiments, subject to shock, 3^4. 307. Rittinger pumps, 133. "308. ,, Rankine, River Ouse Middle Level syphons, 322.

,, Tliomjjson's experi- Rotative engines, 13.

ments, 307. ,, engine valve gears, 213. , ,

334 INDEX.

Saarbettoken hydraulic pumping-engine, Steam distribution, combined high and low 176. pressure systems, 46, Savery pumping-engine, 1, 12. 47. of, 2. of, 44. „ „ ,, description ,, ,, diagrams

duty of, 16. ,, ,, explanation of, 45.

Scoop wheels, 298. ,, engine, back pressure, 29. atHalfweg, 298. Branca, 1.

,, atZeeburg, 299. clearance, 29.

,, at Zuidplas, 300. cylinder condensation, 28. losses, ,, ,, compared with lift and diagram illustrating centrifugal pumps, 301. 28. frictional losses, ,, ,, construction of, 299. 31.

,, ,, cost of, 301. Hero, 1.

,, ,, efficiency of, 300. in Cornwall, Watt, 17- formula for, 300. 20. Separate condenser. Watt's experiments, incomplete expansion, 30. 14. leakage, 31. Sewage works, Cambridge, pumping- priming and radiation, engine, 269, 272. 30.

,, ,, Leicester, pumping- Savery, 1. engine, 249. superheating, 28. Shaft feeders, stopping, 165, 166. trials, 34, 36, 37, 38,

,, sinking, Chapter VIII., 120, 155- 279-297.

173. ,, engines (pumping). Chapter II.,

,, ,, illustration of method, 27.

159. ,, latent heat of. Dr. Black, 14.

,, ,, use of pulsometer, 162, ,, pipes, condensation in, 126.

163. ,, pumps, compound, Birmingham

,, tubbing, 165. waterworks, 262-263.

Shanghai waterworks compound engine, ,, ,, consumption of steam, 257, 261. 126.

Shocks in hydraulic pumps, 192. ,, ,, triple compound, 267,

,, in water columns, 221. 272.

,, ,, ,, mains, 322, 324. ,, ,, underground, 126.

Shutter valve, Davey, 210, 212, 213. ,, ,, valves of, 214.

Sims compound engine, 24. ,, turbine, 1. Sinking lifts, 122, 124, 125, 150, 171. Suction pipe, telescopic, 173.

,, ,, suspension of, 161, 170. Syphons, 319, 320, 321. 162. drainage of fens by, 322. ,, pump, Cameron, ,

,, ,, Zollern colliery, 164. ,, inverted, 321.

Smeaton, duty of atmospheric engine, 13, ,, Middle Level, 322.

17. ,, pumping main, 321.

,, engine at Chacewater, 13, 17.

,, improvements in atmospheric Tanks for bailing, 155-158. engines, 13, 16. Taylor engine at United mines, 25.

Snore pipes, 173. ,, hydraulic air compressor, 317, Sommeiller hydraulic air compressor, 325. 318. Southwark & Vauxhall Water Co. pump- Teague's valve, 56. ing-engine, 290-293. Telescopic suction pipe, 173. Spear rods, 126. Theoretical standard, use of, 33. Steam, consumption of, beam engines, 37, Thermal efficiency, 31, 39. 43. Thompson experiments with centrifrugal compound en- pumps, 307. % gines, 37, 45. Town water supply, 243.

Cornish engines, ,, ,, ,, filter pumps, 243, 244, 37, 94. 303, 305.

engines, various, ,, ,, ,, fiuctuation in demand, 37, 43. 248.

perfect engines, ,, ,, ,, machinery for, 245.

34, 35. ,, ,, ,, pumping from wells, single engines, 37. 245. steam pumps, 45, Trevithick compound engine, 23, 26. Cornish boiler, 23. 128. ,

triple engines, 37. ,, water pressure engine, 221. underground en- Trials of engines, 34, 36, 37, 38, 279- gines, 126, 128, 297. 132, 134, 136. Trip gear, 206, 207. INDEX. 335

Triple compound steam pumps, 267, Water pressure, engines, A. D. lead mine, 272. 229-234.

,, expansion engine, American, 268, ,, engines, efficiency of, 226, 272. 229, 231, 234.

,, expansion engine, East London ,, engines, for pumping waterworks, 257, 260, 283, brine, 227-229.

285. ,, engines, Hutton Henry

,, expansion engine, Hydraulic Power colliery, 234, 235.

Co., 286, 287. ,, engines, inertia of pump-

,, expansion engine, hydraulic power rods, 238, 239.

transmission, 188, 189, 190, ,, engines, inertia of water 193. column, 238.

,, expansion engine, Leavitt, 261, ,, engines, peculiar applica- 264. tions, 234, 235, 236.

,, expansion engine, Leeds water- ,, engines, power valves, works, 250-257. 226, 227, 232, 233.

,, expansion engine, Liverpool ,, engines, Trevithick, 221, waterworks, 288. 222.

,, Odessa expansion engine, Odessa ,, engines, use of, 244.

waterworks, 280-282. ,, engines, useful effect of, 182, 192, 224, 229, 234. Underground pumping-engine, Hugo ,, supply, Birmingham, variation in mine, 130-133. consumption, 246. Unwatering Hooded colliery, 156-158, Waterworks engines. Chapter XIIL, 165-173. 243. beam, 245, 247, 248, Valve gear, balancing or shutter, 210, 249. 212, 213. ,, ,, Boulton & Watt, Cornish, 48, 49. ,, cam, 214, 215, 216. ,, ,, cross compound rota- ,, Corliss, 29, 211, 212, 213, 214, 219, 220. tive, 257, 261. ,, ,, non -rotative, 258, ,, Cornisli, 88, 92, 203. 260-262, 263, 266. ,, ,, ,, cataract, 205. illustration of, 204. ,, ,, reserve power, 244, ,, ,, ,, 245. ,, ,, coupling two engines, 216. ,, ,, triple expansion, 250, ,, ,, cushioning, 209. 251, 255, 256. ,, Davey diiferential, 205. ,, types dillerential cut off ,, ,, of, 246. ,, ,, ,, Watt, blowing through motion, 209. condenser, 18. bucket pumps, differential expansion, ,, 16. ,, ,, ,, covering 206-209. ,, top of cylinder, 15. exhausting condenser, 18. differential, with cut-oli' ,, ,, ,, ,, expansive and trip gear, 206. ,, power of steam, 14. expansive differential, cylin- ,, working by mechanical ,, ,, ,, with devices, 18. drical slide valves, first engine 208. ,, in Cornwall, 17. ,, introduction into Cornwall, 13. ,, ,, duplex, 213. ,, invention of separate condenser, ,, ,, eccentric, 217. 14. ,, ,, rotative engines, 213. ,, latent heat of steam, 14. ,, ,, steam pumps, 214. ,, partnership with Boulton, 15. ,, ,, tumbler weight, 222. patent expired, 18. gears of pumping-engines, Chapter ,, ,, success XL, 203. ,, in Cornwall, 18. surface condenser, 15. Valves (pump), 29, 62, 54, 66, 57, 58, 61, ,, 63-69. Webber, experiments with centrifugal pumps, 308, 310. Weightof bushel of coal, 23, 26. Waihj mine compound Cornish engine, Well pump, Ashley, 59. 97, 109, 110, HI, 136-141. Wells, bore-hole, 261. trial of, Waltham Abbey pumping-engine, ,, ,, Davey system, 265.

283. ,, excavated, 270, 274. at, 286-288. Wapping, pumping-engine ,, ,, lowering pumps into, Water columns, inertia of, 84, 85, 238. 270, 274.

,, ,, shocks in, 221. West engine at Fowey Consols, 25.

,, level indicator, for wells, 271. Wheal Hope, Grose's engine, 24.

,, pressure, cataract gear, 208. Wheal Towan, Grose's engine, 24. 336 INDKX.

Widnes waterworks, bore-hole wells, Wippermann air charger, 74.

267. ,, compound mining engine,

,, ,, bore-hole pumping- 110, 114, 115. engine, 266, 271. Woolf cast iron boilers, 23.

bore-hole pumping- ,, compound engine, 23, 45. engine, trial of, Worthington puinping-engine, compen- 27], 273. sating device, 86. Winding engines, water pressure, A. D. mine, 229-233. Zeebueo scoop wheels, 299. water, 167. Zollern colliery sinking pumps, 164-171.

,, cost of, 15 Znidplas scoop wheels, 300.

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In Large 8vo. Handsome Cloth, Gilt, Uniform with Stability of Ships and Steel Ships (p. 38). With 34 Folding Plates and 468 Illustrations in the Text. 30s. net. The Principles and Practice DOCK ENGINEERING.of By BRYSSON CUNNINGHAM, B.E., Assoc.M.Inst.C.E., Of the Engineers' Department, Mersey Docks and Harbour Board. GENERAL CONTENTS. Historical and Discursive. — Dock Design. — Constructive Appliances. Materials. —Dock and Quay Walls. —Entrance Passages and Locks. Jetties, Wharves, and Piers. — Dock Gates and Caissons.—Transit Sheds and Warehouses. — Dock Bridges. — Graving and Repairing Docks. — Working Equipment of Docks. Index. " We have never seen a more profusely-illustrated ti-eatise. It is a most important standard work, and should be in'the hands of all dock and harbour engineers." Steamship' "Will be of the greatest service to the expert as a book of reference." Engineer.

Fourth Edition. In Two Parts, Published Separately. A TEXT-BOOK OF

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Vol. I. Peactical Gbomktry, Plane, and Solid, ia. 6d. Vol. II. Machine and Engine Drawing and Design. 4s. 6d. BY SIDNEY H. WELLS, Wh.Sc, A.M.I.C.E., A.M.I.Mech.E., Principal of the Batterspa Polytechnic Institute, (fee. With many Illustrations, specially prepared for the Work, and numerous Examples, for the Use of Students in Technical Schools and Colleges. " A CAPITAL TBXT-BOOK, arranged on an bxcbllent system, calculated to give an intelligent

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28 GHARLES ORIFFIN

Works by BRYAN DONKIN, M.Inst.C.E., M.Inst.Meeh.E., &e.

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ENGINEERING AND MEGHANI08, 29

FouETH Edition, Revised and Enlarged. Pocket-Size, Leather., 12s. 6d. Boilers, Marine and Land ." THEIR CONSTRUCTION AND STRENGTH. A Handbook of Rules, FormuIuE, Tables, ko., relative to Material,. Scantlings, and Pressures, Safety Valves, Sprinos, Fittings and Mountings, &o. FOR THE USE OF ENGINEERS, SURVEYORS, BOILER-MAKERS, AND STEAM USERS. By T. W. TRAILL, M. Inst. O.E., F. E. R. N., Late Engineer Surveyor-in-Chief to the Board of Trade. •»* To THE Second and Third Editions many New Tables for Pressure, up to 200 Lbs. per Square Inch have been added. Thb most valdablb woee on Boilers publisiied in England."—SAijjjnnp World. Oontains an Enorwous Quantity op Ikformation arnanged in a very conveDient form.

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Fourth I?npression. Large Crown 8vo. With numerous Illustrations. 63.

ENGINE-ROOM PRACTICE i A Handbook for Engineers and Offleers in the Royal Navy and Mercantile Marine, Including the Management of the Main and Auxiliary Engines on Board Ship. By JOHN G. LIVERSIDGE, A.M.I.C.E., Commander Engineer, Malta. Contents.— Genevnl Deacription of Marine Machinery.—The Conditions of Service and jJutiee of Engineers of the Royal Navy. —Entry and ConditionB of Service of Engiueerb of the Leading S.S. Companies. —Raising Steam —Duties of a Steaming Watch on Engines and Boilara. — Shutting off Steam —Harbour Duties and Watches. —Adjustments and Bepaira of Engines. — Preservation and Repairs of "Tank" Boilei-a.- The Bull and ita Fittings. — Cleaning and Painting Machinery. —Reciprocating Pumps, Feed Heaters, and Automatic Feed - Water Regulators. — Evaporators. — Steam Koats. — Electric Lifrht Machinery. —Hydraulic Machinery,— Air-Compressing Pumps —Refrigerating Machines —Machinery of Destroyers.—The Management of Water-Tube Boil6rs.--Regulation8 foi ''Intry of Assistant Engineers, R.N. —Questions given in Examinations for Promotion of fingineers. R.N. —Regulations respecting Board of Trade Examinations for Engineers, &c. " The contents cannot fail to be appreciated."— 77je Sleamskip

"This VEET USEFUL BOOK. . . . iLLDSTaATiONS are of GEEAT IMPORTANCE in a work of this kind, and it is satisfactory to find that special attention has been given in this respect." Engineers' Gazette. Ill LargeOILCrown 8vo, Cloth.FUEL:Fully Illustrated. 5s. net. ITS SUPPLY, COMPOSITION, AND APPLICATION. By SIDNEY H. NORTH, LATE EDITOR OP THE ''PETROLEUM REVIEW." Contents.—The Sources of Supply.—Economic Aspect of Liquid Fuel.—Chemical Composition ol Fuel Oils —Conditions of Combustion in Oil Fuel Furnaces.—Early Methods and Experiments.—Modern Burners and Methods.— Oil Fuel for Marine Pur- poses. —For Naval Purposes. —On Locomotlves.—For Metallurgical and other Purjwses. —Appendices. —Index. *' Everyone interested in this important question will welcome Mr. North's excellent text-book."—JV^a(wre.

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30 CHARLES GRIFFIN

Second Edition, Revised. With numerous Plates reduced from Working Drawings and 280 Illustrations in the Text. 21s. A MANUAL OF LOCOMOTIVE ENGINEERING: A Praetieal Text-Book for the Use of Engine Builders, Designers and Drauglitsmen, Railway Engineers, and Students. BY WILLIAM FRANK PETTIGREW, M.Inst.C.E. With a Section on American and Continental Engines. By albert F. RAVENSHEAR, B.Sc, Of His Majesty's Patent Office.

Contents, — Hiatorical Introduction, 1763-1863. — Modern LocomotiTes : Simple. — Modem LocomotiTes: Compound. Primary Consideration in l..ocomotiv6 Design. Cylinders, Steam OhestB, and StufQng Boxes. —Pistons, Piston Kods, Orossheada, and Stde Bars. —Connecting and Coupling Rods. —Wfleels and Axlea, Axle Boxes, Horublocks, >nd Bearing Springs. — Balancing. — Valve Gear. — Slide Valves and Valve Gear Details. Framing, Bogies and Axle Trucks, Radial Axle Boxes.— Boilers.— Smokebox. Blast Pipe, E^ebox Fittings. —Boiler Mountings.— Tenders. - Railway Brakes,— Lubrication.— Con- Gumption of Fuel, Evaporation and Engine Efficiency. —American Locomotives.—Con- tinental Locomotives, —Repairs, Running, Inspection, and Renewals. —Three Appendices, —Index. " Likely to remain for many years the Standard Woke for those wishing to learn Design.'* Evgineer. " A most interesting and valuable addition to the bibliography of the Locomotive." Railway Offtcial. Qazette. " We recommend the book as thoroughly practical in its character, and meeiting a

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In Large Svo. Handsome Cloth. With Plates and Illustrations. 16s. L I G ii T HJIl I IL. IHT iL Y S AT HOME AND ABROAD. By WILLIAM HENRY OOLE, M.Inst.O.E., Late Deputy-Manager, North-Westem Railway, India. Consents. —Discussion of the Term "Light Railways."—English Railways, Rates, and Farmers. — Light Railways in Belgium, France, Italy, other European Countries, America and the Colonies, India, Ireland. —Road Trans- port as an alternative. —The Light Railways Act, 1896. —The Question of Gauge.—Construction and Working. —Locomotives and RoUing-Stock. —Light Railways in England, Scotland, and Wales. —Appendices and Index, "Mr. W. H. Cole has brought together ... a large amount of valuable informa-

tion . . . hitherto practically inaccessible to the ordinary reader." Times. ""Will remain, for some time yet, a Standard Work in everything relating to Light Railways. " Engineer. " The author has extended practical experience that makes Ihe book lucid and useful. It is EXCEEDINGLY Well done." Engineering. "The whole subject ia exhaustively and praoticallt considered. The work can be cordially recommended as inpispensable to those whose duty it is to become acquainted with one of the prime necessities of the immediate future." Railway Official Qazette. " There could be no, better book of first reference on its subject. All classes of Engineers will welcome its appearance." Scotsman.

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ENGINEERING AND MECHANICS. 31

FODETH Edition, Thoroughly Revised and Greatly Enlarged. With Numerous Illustrations. Price 10s. 6d. VALVES AND VALVE-GEARING: A PRACTICAL TEXT-BOOK FOR THE USE OF ENGINEERS, DRAUGHTSMEN, AND STUDENTS. By CHARLES HURST, Practical Draughtsman.

PART I.—Steam Eng-ine Valves. PART II.—Gas Eng-ine Valves and Gears. PART III.—Aip Compressop Valves and Gearing. PART IV.—Pump Valves. "Ma. HUBSTS VALVES and valve-qbaeing will prove a very valuable aid, and tend te the production of Engines of scientific design and rcokomical working. . Will be largely sought after by Students and Designers."—Jl/a?-iJie Engiruer. "Almost EVERY TYPE of VALVE and itB geann;^ is clearly set forth, and illustrated in Buch a way as to be readily understood and practically applied by either the Engineer,

Draughtaman, or Student. . . . Should prove both useful and valuable to all Engineers seeking for reliable and cleae information on the subject. Its moderate price brings it within the reach of aU." industries and Iron.

Hints on Steam Engrine Desfgrn and Construction. By Ghakles Hurst, "Author of Valves and Valve Gearing." Second Edition, Revised. In Paper Boards, 8vo., Cloth Back, Illustrated. Price Is, 6d. net.

Contents — I. Steam Pipes,— II. Valves.— III. C\iinders. —IV, Air Pumps and Con- densers. -V. Motion Work.—VI. Crank Shafts and Pedestals.—VII. Valve Gear.—VIIJ Lubrication.—IX. Miscellaneous Details —Index. "A handy volume which every practical young engineer should posse ss."^27i« Model Engineer. _^_^^ _^_„___

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For Calculating' Wages on the Bonus or Premium Systems. For Engineering, Technical and Allied Trades. By henry a. GOLDING, A.M.Inst.M.E., Technical Assistant to Messrs. Bryan Donkin and Clench, Ltd., and Assistant Lecturer in Mechanical Engineering at the Northampton Institute, London, E-C. "Cannot fail to prove practically serviceable to those for whom they have been designed . " Scotsman.

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32 CHARLES GRIFFIN

Shortly. Second Edition. Large 8vo, Handsome Cloth. With Illustrations, Tables, &c. Lubrication & Lubricants A TREATISE ON THE THEORY AND PRACTICE OF LUBRICATION AND ON THE NATURE, PROPERTIES, AND TESTING OF LUBRICANTS By LEONARD ARCHBUTT, RI.O., F.O.S., Chemist to the Midland Railway Company,

R. MOUNTFORD DEELEY, M.I.Mech.E., F.G.S., Chief Locomotive Superintendent, Midland Railway Company.

Contents. —I. Friction of Solids. —II. Liquid Friction or Viscosity, and Plastic Friction. —III. Superficial Tension. —IV. The Theory of Lubrication. —V. Lubricants, their Sources, Preparation, and Properties.—VI. Physical Properties and Methods of Examination of Lubricants. —VII. Chemical Properties and Methods of Examination of Lubricants. —VIII. The Systematic Testing of Lubricants by Physical and Chemical Methods.—IX. The Mechanical Testing of Lubricants. —X. The Design and Lubrication of Bearings. —XI. The Lubrication of Machinery. —INDEX. " Destined to become a CLASSIC on the subject." Industries and Iron. "Contains practically ALL THAT IS known on the subject. Deserves the careful attention of all Engineers." Railway Official Chiide,

Fourth Edition. Very fvlly Illustrated. Glothy 4s. 6(i. STEAM « BOI LE RS? theik defects, management, and constructiojs By R D. MUNRO, Chief Engineer of the Scottish Boiler Insurance and EngiTie Inspection Company

General Contents.— I. Explosions caused (i) by Overheating of Plates—(2) By Defective and Overloaded Safety Valves—(3) By Corrosion, Internal or External—(4) By Defective Design and Construction (Unsupported Flue Tubes; Unstrengthened Manholes Defective Staying; Strength of Rivetted Joints; Factor of Safety)— 11, Construction of Vertical Boilers: Shells—Crown Plates and Uptake Tubes—Man-Holes, Mud-Holes, and Fire-Holes — Fireboxes — Mountings — Management — Cleaning — Table of Bursting Pressures of Steel Boilers—Table of Rivetted Joints— Specifications and Drawings of

Lancashire Boiler for Working Pressures (a) 80 lbs. ; (3) 200 lbs. per square inch respectively. " A valuable companion for workmen and engineers engaged about Steam Boilers, ought to be carefully studied, and always at hand."— Co/I. Guardian. *' The book is very useful, especially to steam users, artisans, and young Engineers." — Engineer.

By the same Author. KITCHEN BOILER EXPLOSIONS: Why they Occur, and How to Prevent their Occurrence. A Practical Hand- book based on Actual Experiment. With Diagram and Coloured Plate. Price ^s.

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In Three Parts. Crown 8vo, Handsome Cloth. Very Fully Illustrated. MOTOR-CAR MECHANISM AND MANAGEMENT. By W. POYNTER ADAMS, M.Inst.E.E.

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Computed to Four Places of Decimals for every Minute of Angle up to 100 of Distance. For the Use of Surveyors and Engineers. By RICHARD LLOYD GURDEN, Authorised Surveyor for the Governments of New South Wales ano Victoria. *^* Published with the Concurrence oj the Surveyors- General for New ^outh Wales and Victoria.

*' Those who have experience in exact Survey-work will best know how to appreciate the enormous amount of labour represented by this valuable book. The computationE enable the user to ascertain the sines and cosines for a distance of twelve miles to within half an inch, and this by refhrence to but One Table, in place ot the usual Fifteen minute computations required. This alone is evidence of the assistance which the Tables ensure to every user, and as every Surveyor in active practice has felt the want of such assistance few knowing of their publication will remain withol't them." —Sngifzeev

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34 CHARLES GRIFFIN & GO.'S PUBLIGATIONS. WOBKS BY ANDREW JAMIESON, M.Inst.C.E., M.I.E.E., F.R.S.E., FoTtnerly Professor of Klectrical En^irteering^ The Glasgow and W^est of Scotland Technical College.

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540 Examination Questions : The Principle of Work and its applica- tions; Part II.: Friction; Gearing, &c. FIFTH Edition. 8s. 6d. ** Fully maintains the reputation of the Author," Praci, EngT-tteer.

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PROFESSOR JAMIESON'S INTRODUCTORY MANUALS Crown Svo. With Illustrations and Examination Papers. STEAM AND THE STEAM-ENGINE (Elementary Manual of). For First- Year Students. Tenth Edition, Revised. 3/6. *' Should be in the hands of every engineering apprentice" Practical Engineer MAGNETISM AND ELECTRICITY (ElementaFy Manual oi). For First-Year Students. Sixth Edition. 3/6. " A CAPITAL TEXT-BOOK . . . The diagrams are an important feature." Schoolmaster. "A THOROUGHLY TRUSTWORTHY Text-boolc. PRACTICAL and clear." Nature. APPLIED MECHANICS (Elementary Manual of). Specially arranged for First- Year Students. Sixth Edition, Revised and Greatly Enlarged. 3/6. " The work has very high qualities, which may be condensed into the one word CLEAR.' " Science aTtd Art.

A POCKET-BOOK of ELECTRICAL RULES and TABLES. For the Use of Electricians and Engineers. By John Monro, C.E., and Prof. Jamieson. Pocket Size. Leather, 8s. 6d. Seventeenth Edition. [See p. 48.

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ENGINEBRINO AND MECHANICS. 35. WORKS BY

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Late Regius Professor of dull Engineering In the Unloerslty of Qlasgoui.

THOROUGHLY REVISED BY

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A MANUAL OF APPLIED MECHANICS :

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A MANUAL OF THE STEAM-ENGINE AND OTHER PRIME MOVERS

With a Section on Gas, Oil, and Air Engines, by Bryan Donkin, M.Iust.C.E. With Folding Plates and Numerous Illustrations. Crown 8vo, cloth. Sixteenth Edition. 12s. 6d.

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Prof. Rankine's Works—(Continued). USEFUL RULES AND TABLES

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A MECHANICAL TEXT-BOOK

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MISCELLANEOUS SCIENTIFIC PAPERS.

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With Memoir by Professor Tait, M.A. Edited by W. J. Millar, O.E. With fine Portrait on Steel, Plates, and Diagrams.

" No more enduring Memorial of Professor Rankine could be devised than the publicA- don of these papers in an accessible form. . . . The Collection is most valuable on account of the nature of his discoveries, and the beauty and completeness of his analysis.

, . . The Voliune exceeds in importance any work in the same department published in our time." Architect,

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Third Edition, Thoroughly Revised and Enlarged. With 60 Plates and Numerous Illustrations. Handso7ne Cloth. 5^. HYDRAULIC POWER AND HYDRAULIC MACHINERY. BY HENRY ROBINSON, M. Inst. C.E., F.G.S.,

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Low-Lift Pumps— Hydraulic Rams, Pumping Mains, &c. Index. ; "By the 'one English Engineer who probably knows more about Pumping Machinery than ANT OTHER.' . . A VOLUME BECOEDING THE EESULTS OP LONG EXPERIENCE AMD STUDY." The Engineer. "Undoubtedly THE BEST amd most practical treatise on Pumping Machinery that has YET BEEN PUBLISHED." Mining Jownal.

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38 CHARLES GRIFFIN 4& GO:S PUBLICATIONS.

Rouaf 8vo, Handsome Cloth. With numerous Illustrations and Tables. 258. THE STABILITY OF SHIPS. BY

SIR EDWARD J. REED, K.C.B., F.R.S., M.P.,

CHIGHT OF THK IMPBRIAL ORDERS OF ST. STANILAUS OF RUSSIA ; FRANCIS JOSEPH OF

AUSTRIA ; MHDJIDIE OF TURKEY ; AND RISING SUN OF JAPAN ; VICB- PRESIDHNT OF THE INSTITUTION OF NAVAL ARCHITECTS. In order to render the work complete for the purposes of the Shipbuilder, whether at home or abroad, the Methods of Calculation introduced by Mr. F. K. Barnes, Mr. Gray, M. Reech, M. Daymard and Mr. Benjamin, are all given separately, illustrated bj Tables and worked-out examples The book contains more than 200 Diagrams, and is Illustrated by a large number of actual cases, derived from ships of all descriptions. " Sir Edward Reed's 'Stability of Ships' is invaluable. The Naval Architect will find brought togetner and ready to his hand, a mass of information which he would other- wise have to seek in an almost endless variety of pubhcations, and some of which he would possibly not be able to obtain at all elsewhere." Siea-mskip.

THE DESIGN AND CONSTBTJCTION OF SHIPS. By John Harvard Biles, M.Inst.N.A., Professor of Naval Architecture in the University of Glasgow. [/w Preparation.

Third Edition. Illustrated with Plates, Numerous Diagrams, and Figures in the Text. i8s. net. STEEL SHI PSj THSIR CONSTRUCTION AND MAINTENANCE. A Manual for Shipbuilders, Ship Superintendents, Students, and Marine Engineers. By THOMAS WALTON, Naval Architect, author of "know YOUR OWN SHIP." Contents. —I. Manufacture of Cast Iron, Wrought Iron, and Steel. —Com- oosition of Iron and Steel, Quality, Strength, Tests, &c. II. Classification of Steel Ships. III. Considerations in making choice of Type of Vessel. —Framing of Ships. IV. Strains experienced by Ships. —Methods of Computing and Comparing Strengths of Ships. V. Construction of Ships. —Alternative Modes of Construction. —Types of Vessels. —Turret, Self Trimming, and Trunk Steamers, &c. —Rivets and Kivetting, Workmanship. VI. Pumping Arrange- ments. VII. Maintenance. —Prevention of Deterioration in the Hulls of Ships. — Cement, Paint, &c. — Indes. ' So thorouiih and we 1 written is every chapter in the book that it i-^ diilicult to select any of them as being worthy of exceptional pra se. Altogether, the work is excellent, and will prove of areat ?a ue to those for whom it is intended." — T/ie Engineer. "Mr Walton has written for the profession of which he is an ornament. His work will be read and appveciati'd. no doubt, by every M.LN-A,, and with great benefit by the majority of them." Journal of Gommtrce. UNIFORM WITH THE ABOVE, DOCKTHE PRINCIPLESENGINEERING.AND PRACTICE OF By BRYSSON CUNNINGHAM, B.E., M.Inst.C.E. See p. 27.

LONDON: CHARLES GRIFFIN & CO.. LIMITED, EXETER STREET, STRAND. — — —— ;

NAUTICAL WORKS. 39 GRIFFIN'S NAUTICAL SERIES. Edited by E D W. BLACKMORE, Master Mariner, First Class Trinity House Certificate, Assoc. Inst. N.A. And Weitten, mainly, by Sailors for Sailors.

"This admirable series."—Fairpiay. "A tert useful series."—.Sfaiure. "The volumes of Me.'ssrs. Griffin's Nadtical Series may well and profitably be read by ALL interested in our NATIONAL MARITIME progress " Marine Engineer. "Every Ship should have the whole Series as a Reference Library. Hand- somely BOUND, CLEARLY PRINTED and ILLUSTRATED."— Z-ijjcrpooi Journ. of Cormnerce.

its The British Mercantile Marine : An Historical Sketch of Rise and Development. By the EiilTOR, Capt. BLACKMORE. THIRD Edition. 3s. 6d. " Captain Blackmore's SPLENDID BOOK . . . contains paragraphs on every point Of interest to the Merchant Marine. The 243 pages of this book are THE MOST VALU- ABLE to the sea captain that have EVER been compiled."—Merchant Service Review.

Elementary Seamanship. By D. Wilson-Bakker, Master Mariner, F.R.S.E., F.R.G.S. With numerous Plates, two in Colours, and Frontispiece. Fourth Edition, Thoroughly Revised. With additional Illustrations. 6s. "This admirable manual, by Capt. Wilson Barker, of the ' Worcester,' seems to us perfectly designed."—AtheiioBum.

Know Your Own Ship : A Simple Explanation of the Stability, Con- struction, Tonnage, and Freeboard of Ships. By THOa. Walton, Naval Architect. With numerous Illustrations and additional Chapters on Buoyancy, Trim, and Calculations. Eighth Edition. Ts. 6d. "Mr. Walton's book will be found very useful." —The Engineer.

Navigation : Theoretical and Practical. By D. Wilson-Barker and William Allingham. Second Edition, Revised. 3s. 6d. " Precisely the kind of work required for the New Certificates of competency. Candidates will find it INVAhxj A.iiLE."— Dunden Advertiser.

Marine Meteorology : For Officers of the Merchant Navy. By William Allin'JHAm, Fi'-st Class Honours, Navigation, Science and Art Department. With Illustrations, Maps, and Diagrams, and facsiinile reproduction of log page, 7s. 6d. " Quite the best publication on tliis subject." Shipj^ing Gazette-.

Latitude and Longitude : How to find them. By W. J. Millar, C.E. Second Edition, Reviseil. 2s. " Cannot but prove an acquisition to those studying Navigation." Marine Engineer.

Practical Mechanics : Applied to the requirements of the Sailor. By Thos. Mackenzie, Master Mariner, F.R.A.S. Second Edition, Revised. 3s. ed. " Well WORTH the money . . . exceedingly helpful."—Shipping World.

Trigonometry : For the Young Sailor, &,c. By Rich. C. BnCK, of the Thames Nautical Training College, H.M.S. " Worcester." THIRD EDITION, Revised. Price 3s. 6d. "This EMINENTLY PRACTICAL and reliable \o\\irae."—Schoolmaster.

Practical Algebra. By Rich. C. Bcck. Companion Volume to the above, for Sailors and others. Second Edition, Revised. Price 3s. 6d. " It is JUST THE book for the young sailor mindful of progress." Nautical Magazine. The Legal Duties of Shipmasters. By Benbdict Wm. Ginsburq, M.A., LL.D., of the Imier Temple and Northern Circuit; Barrister-at-Law. SECOND Edition, Thoroughly Revised and Enlarg.^d. Price 4s. 6d. " Invaluable to uiasters. . We can fully recommend it." Shipping Gazette.

A Medical and Surgical Help for Shipmasters. Including First Aid at Sea. By Wm. -Iohnson Smith, F.R.C S., Principal Medical Officer, Seamen's Hospital, Greenwich. Third Edition, Thoroughly Revised. 6s. "Sound, judicious, really helpful."— '/"Ae Lancet.

LONDON: CHARLES GRIFFIN & CO., LIMITED, EXETER STREET, STRAND. 2 — —

40 GHAELES OEIFFIN

GRIFFIN'S NAUTICAL SERIES .

Introductory Volume. Price 3s. 6d.

British Mercantile Marine. By EDWARD BLACKMORE, MASTER MARINER; ASSOCIATE OF THE INSTITUTION OF NAVAL ARCHITECTS; MEMBER OF THE INSTITUTION OF ENGINEERS AND SHIPBUILDERS IN SCOTLAND;— EDITOR OF GRIFFIN'S "NAUTICAL SERIES." General Contents. Histokical : From Early Times to 1486— Progress ander Henry VIII. —To Death of Mary—During Elizabeth's Eeign—Up to the Keign of William III.—The 18th and 19th Centuries— Institution of Examinations — Kise and Progress of Steam Propulsion — Development of Free Trade— Shipping Legislation, 1862 to 1875—" Locksley Hall" Case Shipmasters' Societies—Loading of Ships—Shipping Legislation, 1884 to 1894

Statistics of Shipping. The Peksonnbl : Shipowners— Officers—Mariners

Duties and Present Position. Education : A Seaman's Education : what it should be—Present Means of Education—Hints. Discipline and Duty— Postscript—The Serious Decrease in the Number of British Seamen, a Matter demanding the Attention of the Nation. " Interesting and Iksteuctive . . may be read with profit and enjotment."- 9lasgovi Berald. "Every brai^ch of the subject is dealt with in a way which shows that the writer 'knows the ropes' familiarly."—5coisman. " This admirable book . . , teems with aseful information—Shoiild be in the hands of every Sailor." Weslern Morning News.

Fourth Edition, Thoroughly Eevised. With Additional Illustrations. Price 6s. ELEMENTARY SEAMANSHIP. BY D. WILSON-BARKER, Master Mariner; F.R.S.E., F.R.G.S.,&c., &o. TOnNGER BEOTHEB OF THE TRINITY HODSE. With Frontispiece, Numerous Plates (Two in Colours), and Illustrations in the Text. General Contents. —The Building of a Ship; Parts of Hull. Masts, &c. —Ropes, Knots, Splicing, &c. — Gear, Lead and Log, &c. — Rigging, Anchors — Sailmakong — The SaUs, &c. — Handling of Boats under Sail — Signals and Signalling—Rule of the Road— Keeping and Relieving Watch Points of Etiquette—Glossary of Sea Terms and Phrases—Index. *,* The volume contains the new rules of the road. **This admirable manual, by Capt, Wilson-Baeker of the 'Worcester,' seems to ub

pbefectly desiqked. and holds its place excellently in 'Griffin's Nauticax Series.' . , . Although intended for those who are to become OfBcers of the Merchant Navy, it will be found useful by all yachtsmen."—Athenseum.

*»* For complete List of Griffin's Nautical Series, see p. 39,

LONDON : CHARLES GRIFFIN & CO., LIMITED. EXETER STREET, STRAND. ——"

NAOTIGAL WORKS. 41

GRIFFIN'S NAUTICAL SERIES.

Second Edition, Revised and Illustrated. Price Ss. 6d.

JPItACTICAIL, RJH-D THEORETICAL..

By DAVID WILSON-BARKER, R.N.R., F.R.S.E, &c.,

from Second Mate to eitra Master. . . Candidates will find it invaluable. "—^«ndM Advertiser. " A CAPITAL LITTLE BOOK . . . Specially adapted to the New Examinations. The Authors are Capt. WiLSON-BAfiKBH (Captain-Superintendent of the Nautical College, H.M.S. ' Worcester,' who has had great experience in the highest problems of Navigation), and Mr. Allingham, a well-known writer on the Science of Navigation and Nautical Astronomy. — Shipping World.

Handsome Cloth. Fully Illustrated. Price 7s. 6d. MARINE METEOROLOGY, FOR OFFICERS OF THE MERCHANT NAVY. By WILLIAM ALLINGHAM, Joint Author of "Navigation, Theoretical and Practical."

With numerous Plates, Maps, Diagrams, and Illustrations, and a facsimile Reproduction of a Page from an actual Meteorological Log-Book. SUMMARY OF CONTENTS. Introductory.—Instruments Used at Sea for Meteorological Purposes.—Meteoro- logical Log-Books. —Atmospheric Pressure. —Air Temperatures. —Sea Temperatures. Winds.—Wind force Scales.—History of the Law of Storms.—Hurricanes, Seasons, and Storm Tracks.—Solution of the Cyclone Problem.-Ocean Currents.—Icebergs.—Syn- chronous Charts.—Dew, Mists, Fogs, and Haze.—Clouds.—Kain, Snow, and Hail.— Mirage, Rainbows, Coronas, Halos, ana Meteors.-Lightning, Corposants, and Auroras. Questions. —Appendix, —Index. * Quite the best publication, and certainly the most imteeestiho, on this subject ever presented to Nautical meti."—Shipping Gazette.

*^* For Complete List of Grtffin's Nautical Series, see p. 39.

LONDON: CHARLES GRIFFIN & CO.. LIMITED. EXETER STREET, STRAND. — —:":

4a OHARLEH GRIFFIN A OO.'S PUBLICATIONS. GRirFINS NAUTICAL SERIES.

Second Edition, Revised. With Numerous Illustrations. Price 3s. 6cU. Practical Mechanics: Applied to the Bequirements of tJie Sailor. By THOS. MACKENZIE, Master Mariner^ F.R.A.S. General Contents. —Eesolution and Composition of Forces—Work done by Macliines and Living Agents—The Mechanical Powers: The Lever;

Derricks as Bent Levers—The Wheel and Axle: Windlass ; Ship's Capstan;. Crab Winch—Tackles: the "Old Man"—The Inclined Plane; tlie Screw

The Centre of Gravity of a Ship and Cargo — Relative Strength of Rope : Steel Wire, Manilla, Hemp, Coir—Derricks and Shears- Calculation of the Cross- breaking Strain of Fir Spar—Centre of Effort of Sails—Hydrostatics the Diving-bell ; StabUity of Floating Bodies ; the Ship's Pump, &c. " This excellent book , . . contains a large amount of information. —Nature.

" . — Well woeth the money . . wiU be found exceedingly helpful." Shipping World. No Ships' Officees' bookcase will henceforth be complete without Captain Mackenzie's ' Peaotical Mechanics.' Notvrithstanding my many years' experience at sea, it has told me liow much more tltera is to acquire."— (Letter to the Pubhshers from a Master Mariner) *' I must express my thanks to you for the labour and care you have takep

In 'Practical Mechanics.' . . . It is a life's experience. . . What an amount we frequently see wasted by ringing purchases without reason

' ' and accidents to spars, &c., &c. ! Practical SIechanics would save all THIS. " —(Letter to the Author from another Master Mariner).

WORKS BY RICHARD C. BUCK, of the Thames Nautieal Training College, H.M.S. ' Worcester.' A Manual of Trigonometry With Diagrams, Examples, and Exercises. Price 3s. 6d. Third Edition, Revised and Corrected. *,* Mr. Buck's Text-Book has been specially prepared with a view to the New Examinations of the Board of Trade, in which Trigonometry is an obligatory subject. "This EMINENTLY PRACTICAL and RELIABLE VOLUBIE." Schoolmaster. A Manual of Algebra. Designed fo meet the Requirements of Sailors and otiiers. Second Edition, Revised. Price 3s. 6d. %* These elementary works on algebha and trigonometry are written specially for those who will have little opporrunitv of consulting a Teach^. Tbey are books for "sklf HELP." All but the simplest explanations have, therefore, ween avoided, and answers t9 the Exercises are ^ven. Any person may readily, by careful study, become master of thol* contents, and thus lay the foiiodation for a further mathematical course, if desired. It is hoped that to the younger OfRcers of our Mercantile Marine thoy will be found decidedly serviceable The Examples and Exercises are taken from the Examination Papers set for the Oadets of the "Worcester.' "Clearly arranged, and well got up. A flrst-rate Elementary Algebra. — Nautical Magazine. ,*For complete List of Griffin's Naottcal Sbeies. see p. 39.

LONDON: CHARLES GRIFFIN & CO., LIMITED, EXETER. STREET, STRAND. —— — :

NAUTICAL WORKS. 43 GRIFFIN'S NAUTICAL SEBIES. Second Edition, Thoroughly Revised and Extended. In Crown 8vo. Handsome Cloth. Price 4s. 6d. THE LEGAL DUTIES OF SHIPMASTERS. BY BENEDICT WM. GINSBUKG, M.A., LL.D. (Cantab.), Of the Inner Temple and Northern Circuit; Barrister- at-Law. General Contents.—The Qualification for the Position of Shipmaster—The Con- tract with the Shipowner—The Master's Duty in respect of the Crew: Engagement;

Apprentices; Discipline; Provisions, Accommodation, and Medical Comforts ; Payment of Wages and Discharge—The Master's Duty in respect of the Passengers—The Master's Financial Responsibilities—The Master's Duty in respect of the Cargo—The Master's Duty in Case of Casualty—The Master's Duty to certain Public Authorities—The Master's Duty in relation to Pilots, Signals, Flags, and Light Dues—The Master's Duty upon Arrival at the Port of Discharge—Appendices relative to certain Legal Matters Board of Trade Certificates, Dietary Scales, Stowage of Grain Cargoes, Load Line Regula- tions, Life-saving Appliances, Carriage of Cattle at Sea, tfec, &c. —Copious Index. " No Intelligent Master ahonld fail to add this to his list of necessary books, A few lines of It may save a lawtke's fee, besides endless woekt."—Xiwerpoo/ Journal of Commerce. "Sensible, plainly written, in clear and non-technical LAijoDACE, and will be found of MDOH service by the Shipmaster." British Trade Review.

Skcond Edition, Revised. With Diagrams. Price 2s. Latitude and Longitude: Ho^HT to FiMi^ tlieirYi. By W. J. MILLAR, C.E., Late Secretary to the Inst, of Ejigmeers and Shipbuilders in Scotland.

"' Concisely and clearly written . . . cannot but prove an acquisition to those studying Navigation. " Marine Engineer. " Young Seamen will find it handy and USEFUL, SIMPLE and CLEAK."— The Engineer. FIRST AID AT SEA. Third Edition, Revised. With Coloured Plates and Numerous Illustra- tions, and comprising the latest Regulations Respecting the Carriage of Medical Stores on Board Ship. Price 6s. A MEDICAL AND SURGICAL HELP FOR SHIPMASTERS AND OFFICERS IN THE MERCHANT NAVY. EY WM. JOHNSON SMITH, F.R.O.S., Principal Medical Officer, Seamen's Hospital, Greenwich. %* The attention of ail interested in our Merchant Navy is requested to this exceedingly aaeful and valuable work. It is needless to say that it ia the outcome of many years PRACTICAL EXPERIENCE amongst Seamen. " SooND, JUDICIOUS, EEALLT HELPFUL " The Lancet

*^* For Complete List of Griffin's Nautical Series, see p. 39

LONDON: CHARLES GRIFFIN & CO., LIMITED, EXETER STREET, STRAO, — — —

44 CHARLES GRIFFIN dk GO.'S PUBLICATIONS. GRTFFm'S NAUTICAL SERIES. Eighth Edition. Revised, tcith Chapters on Trim, Buoyancy, and Calcula- tions. Numerous Illustrations. HandsoTne Cloth, Crown Svo. Price 7s. 6d. KNOW YOUR OWN SHIP. By THOMAS WALTON, Naval Architect.

Specially arranged to suit the requirements of Ships' Officers, Shipowners, Superintendents, Draughtsmen, Engineers, and Others, This work explains, in a simple manner, such important subjects as: —Displacement- —Deadweight.— Tonnage. — Freeboard. — Moments. — Buoyancy. — Strain. — Stiiicture. Stability.—Rolling. —Ballasting.—Loading.—shifting Cargoes.— Admission of Water. Sail Area.—&c. " The little book will be found exceedikgly handy by most officers and officials connected with shipping. . . . Mr. Walton's work will obtain lasting success, beeause of its uujque fitness for those for whom ifc has been written."—Shijxping World. BY THE SAME AUTHOR.

Steel Ships: Their Constrnction and Maintenance. (See page 38.)

Fifteenth Edition, TliorougMy Revised, Greatly Enlarged, and Reset Throughout. Large Svo, Cloth, pp. i-xxiv + 7US. With 280 Illustra- tions, reduced Jrom, Working Drawings, and 8 Plates. 21s. net. A MAN UAL OF MARINE ENGINEERING: COMPRISING THE DESIGNING, CONSTRUCTION, AND WORKING OF MARINE MACHINERY. By A. E. SEATON, M.I.C.E., M.I.Meeh.E.. M.LN.A. General Contents. — Pakt I. —Principles of Marine Propulsion. Pakt II. — Principles of Steam Engineering. Part III. — Details of

Marine Engines : Design and Calculations for Cylinders, Pistons, Valves, Expansion Valves, &c. Part IV.— Propellers. Part V. — Boilers. Part VI. —Miscellaneous. "The Student, Urau^htamaii, and Engineer will find this work the most valuable Handbook ol Reference on the Marine H^neine now in existence." Marijw EjiQlTicfT.

Eighth Edition, Thoroughly Revised. Pocket-Size, Leather. 8s. 6d. A POCKET-BOOK OF MARINE ENGINEERING ROLES AND TABLES, FOE THE 0SE OF Marine Engineers, Naval Arehiteets, Designers, Draughtsmen Superiniendents and Otheps. By a. E. SEATON, M.I.O.E., M.I.Meeh.E., M.I.N. A., and H. M. ROUNTHWAITE, M.I.Meeh.E., M.LN.A

"Admirably fulfils its purpose." Marine Eneimer.

LONDON: CHARLES GRIFFIN & CO., LIMITED, EXETER STREET, STRAND. — — — :

ENGINElSRINa AND MEGHANWS. 45

WORKS BY PROF. ROBERT H. SMITH, Assoe.M.I.C.E., M.I.M.E., M.LE1,E., M.LMiu.E., Whit. Soh., M.Ord.Meijl THE CALCULUS FOR ENGINEERS AND PHYSICISTS, Applied to Technical Problems. WITH BXTEHSIVE CLASSIFIED BErERENCE LIST OF INTEGRALS. By PROF. ROBERT H. SMITH. ASSISTED BT R. F. MUIRHEAD, M.A., B.Sc,

Formerly Clark Fellow of Glasgow University, and Lecturer on Mathematics at Mason College.

In Grown 8vo, extra^ with Diagrams and Folding- Plate. 8s. 6d. " Paop. R. H. Smith's book will be serviceable in rendering a hard road as east as peactic- ABLE for the non-mathematical Student and Engineer." AtJienceum. * Interesting diagrams, with practical illustrations of actual occurrence, are to be found here In abundance. Thr vest complete classified eeferehce table will prove very useful in saving the time of those who want an integral in a hurry," The Engineer.

MEASUREMENT CONVERSIONS (English and French) 28 GRAPHIC TABLES OR DIAGRAMS. Showing at a glance the Mutual Conversion of Measurements in Different Units Of Lengths, Areas, Volumes, Weights, Stresses, Densities, Quantities of Work, Horse Powers, Temperatures, &c. For the use of Engineers, Surtieyors, Architects, nnd Contractors. In 4to, Boards. 7s. 6d.

*,* Prof. Smith's Conversion-Tables form the most unique and com- prehensive collection ever placed before the profession. By their use much time and labour will be saved, and the chances of error in calculation diminished. It is believed that henceforth no Engineer's Office will be considered complete without them.

" The work is invaluable."—CoUtiry Ovardxan. " Ought to he in EVEay office where even occasional conversions are required. Prof. Smith's Tables form very excellent checks on results."—JSZ«c(rica; lUview. " Prof. Smith deserves the hearty thanlis, not only of the Enoiheeb, but of the Commbecial WoELD, for having smoothed the way for the adoption of the Metric yYSTEM of Measueemenx, a suhject which is now assuming great importance as a factor in maintaining our hold upon rOEBlQN TEADB." The Machinery Market.

LONDON: CHARLES GRIFFIN & CO., LIMITED, EXETER STREET, STRAPSa — — — — —

46 CHARLES GRIFFIN

Second Edition. In Large 8vo. Handsome Cloth. 16s. CHEMISTRY FOR ENGINEERS. BY BERTRAM BLOUNT, and A. G. BLOXAM, F.I.C., F.C.S., A.LC.E., F.I.C., F.C.8., Consulting Cbemiat to the Crown Agents for Consulting Chemist, Head of the Chemistry the Colonies. Department, Goldsmiths' Inst., New Cross. GENERAL CONTENTS.—Introduction— Chemistry of the Chief Materials of Conatr^ction—Sources of Ener^—Chemistry of Steam-raising—Chemis- try of Lubrication and Lubricants— Metallurgical Processes used in the Winning and Manufacture of Metals. "The anthers have bdcceedl^d beyond all eipectstion, and have produced a work which should Rive fresh powee to the Enfjineer and Manufacturer."' Tlie Times. "Phactical thhouqhout ... an admieable text-book, useful not only to Students, but to ENQiMEEas and Makaobes op works in peevhntino waste and imphovino peockssbs."— Scotsman.

For Companion Volume by the same Authors, see " Chemistht FOR Manufacturers," p. 71.

Pocket Size, Leather Limp, with Gilt Edges and Rounded Corners, printed on Special Thin Paper, with Illustrations, pp. i-xii + 834. Price ISs. net. (THE NEW " NYSTROM ") THE MECHANICAL ENGINEER'S REFERENCE BOOK A Handbook of Tables, Formulas and Methods for Engineers, Students and Draughtsmen. By HENKY HARRISON SUPLEE, B.Sc, M.E. Tables, Formulas, and Reference Data for Mechanical Enginpers, comprising machine design and information relating to the drawing office and the designing department; intended as a successor to the weil-known Pocket-Book written many years ago by the late JoUN W. NiSTEOM. Pnbifihfrs' Note.

Works by WALTER R. BROWNE, M.A., M.InslC.E.. THE STUDENT'SLate I'eDow of Trinity College,MECHANICS:Cambridge. An Introduetion to the Study of Force and Motion. With Diagrams. Crown 8vo. Cloth, 4s. 6d.

" Clear in style and practical in method, 'Thh Student's Mechanics' is cordially to be recommended from all points of view," AiheruEum. FOUNDATIONS OF MECHANICS. Papers reprinted from the Engineer^ In Crown 8vo, is.

Demy 8vo, with Numerous Illustrations, 9s. FUEL AND WATfeR: A Manual for Users of Steam and Water. By Prof. FRANZ SCHWACKHOfER of Vienna, and Vv^ALTER R. BROWNE, M.A., CE. Ghnkral Contents.—Heat and Combustion^ Fuel, Varieties of— Firing Arrange-

ments : Furnace, Flues, Chimney — The Boiler, Choice of — Varieties — Feed-water

Heaters—Steam Pipes—Water : Composition, Purification—Prevention of Scale, &c. , &c. "The Section on Heat is one of the best and most liicid ever written." Engineer. " Cannot fail to be valuable to thousands using steam power." Rail-way Engineer.

LONDON: CHARLES GRIFFIN & CO., LIMITED, EXETER STREET, STRAND, —

ENGINEERING AND MEGHANIGS. 47 CRIFFIN'S LOCAL GOVERNMENT HANDBOOKS. WORKS SUITABLE FOR MUNICIPAL AND COUNTY ENGINEERS, ANALYSTS, AND OTHERS.

See also Davies' Hygiene, p. 99, and MacLeod's Calculations, p. 110 (General Catalogue). Gas Manufacture (The Chemistry of). A Handbook on the Pro- duction, Purification, and Testing of Illuminating Gas, and the Assay of Bye-Pro- ducts. By W. J. A. BOTTBRFIELD, M.A., F.I.C., F.C.S. With Illustrations. '1 HIED Edition, Revised. Vol I., 7s. 6d. net. Wo^. 11., in preparation. [See page 77

Water Supply : A Practical Treatise on the Selection of Sources and the Distribution of Water. By Reginald E. Middleton, M.Inst.C.E., SI.Inst.Mech.E., F.S.I. With Numerous Diagram^ and Plates. Crown 8vo. 8s. 6d. net. [See page 77.

Central Electrical Stations : Their Design, Organisation, and Manage- ment. ByC. H. WORDINGHAM, A,K.C.,M.I.C.E. SECOND EDITION. 24s.net. [Seep. 48.

Sewage Disposal Works : A Guide to the Construction of Works for the Prevention of the Pollution by Sewage of Rivers and Estuaries. By W. Santo Crimp, M.Inst.C.K., F.6.S. Skcond Edition, Revised and Enlarged. Large 8vo, Handsome Cloth. With 37 Plates. Price 30s. [See page 76.

Trades' Waste : Its Treatment and Utilisation, with Special Reference to the Prevention of Rivers' Pollution. By W. Naylor, F.C.S., A.M.Inst.C.E. With Numerous Plates, Diagrams, and Illustrations. 21s. uet. [See page 76.

Calcareous Cements : Their Nature, Preparation, and Uses. With some Remarks upon Cement Testing. By Gilbert Redgrave, Assoc. Inst.C.E., and Chas. Spaokman, F.C.S. Witl> Illustrations, Analytical Data, and Appendices on Costs, (fee. 15s. net. [See page 76,

Bead Making and Maintenance : A Practical Treatise for Engineers, Surveyors, and others. With an Historical Slietch of Ancient and Modern Practice. By TuoMAS AlTKEN, Assoc. M.Inst.C.E., M. Assoc. Municipal and County Engrs.; M. San. Inst. With numerous Di.agrams and Illustrations. 21s. [See page 79. Light Railways at Home and Abroad. By William Henky Cole, M.Inst.C.E., late Deputy Manager, North- Western Railway, India. Large 8vo, Handsome Cloth, Plates and illustrations. 16s. r*'^* [See page 30.

Practical Sanitation : A Handbook for Sanitary Inspectors and others iutcrested in Sanitation. By Geo. Reid, M.D., D.P H., Medical OiBcer, Staffordshire

County Council. With Appendix on Sanitary Law, by Herbert Manley, M.A. , M. B., D.P. H. Twelfth Edition, Ihoroughly Revised. 6s. [See page 78. Sanitary Engineering: A Practical Manual of Town Drainage and Sewage and Refuse Disposal. By Francis Wood, A.M.Iust.C.E., F.G.S. Second Edition, Revised. Fully Illustrated. 8s. 6d. net. [See page 78. Dairy Chemistry: A Practical Handbook for Dairy Managers, Chemists, and Analysts. By H. Droop Richmond, F.I.C, Chemist to the Aylesbury Dairy Company. With Tables, Illustrations, &c. Handsome Cloth, 16s. [See page 73.

Dairy Analysis : The Laboratory Book of. By H. Droop Richmond, F.l.C. Fully Illustiated, Cloth. 2s. 6d. net. [See page 73.

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"Should prove a vade-mecum to Mining Engineers and all engaged in practical work. — Iron and Coal Trades Review.

TESTING EXPLOSIVES. By C. E. Bichel and Axel Larsen. Contents. —Historical—Testing Stations—Bower Gauges—Products of Combustion—Heat of Decomposition—Rate of Detonation—Rate and Duration of Flame—After I'lame Rates—Transmission of Explo- sion—-Efficiency, &c. In Medium 8vo. Fully Illustrated. 6s. net. '*Its pages bristle with suggestions and actual experimental results to an extent seldom found in a volume of five times its size." Arras and Explosives

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In Medium 8j)o. With Numerous Plates, Maps, and Illustrations. 2I3. net. GYANIDING GOLD & SILVER ORES.

A Practical Treatise on the Cyanide Process ; its Application, Methods of Working, Design and Construction of Plant, and Costs. By H. FORBES JULIAN,

Mining and Metallurgical Engineer ; Specialist in Gold : Late Technical Adviser of the Deutsche Gold und Silber Bcheide Anstalt, Frankfort-on- Maine. And EDGAR SMA.RT, A.M.I.O.E., Civil and Metallurgical Engineer.

" A handsome volume of 400 pages which will be a valuable book of reference for all associated with the process." Mining Journal. "The authors are to be congratulated upon the production of what should prove to be a standard work." Page's Magazine.

In Large Crown 8uo. With Plates and Illustrations. Handsome Qloth. Is, Qd. THE CYANIDE PROCESS OF GOLD EXTRACTION. A Text-Book for the Use of Metallurgists and Students at Schools of Mines, do. By JAMES PARK, F.G.S., M.Inst.M.M., Professor Mining and Director of the Otago University of School of Mines ; late Director Thames School of Mines, and Geological Surveyor and Mining Geologist to the Governnieut of New Zealand. Third English Edition. Thoroughly Re\'ised and Greatly Enlarged. With additional details concerning the Siemens-Halske and other recent processes. " Deserves to be ranked as amongst the BEST OF existing TREATISES."— J/ini?!^ JourjMtJ. Third Edition,GETTINGRevised. With Plates andGOLD:Illustrations. Cloth, 3s. Sd. A GOLD-MINING HANDBOOK FOR PRACTICAL MEN. By J. 0. F. JOHNSON, F.G.S., A.I.M.E., Life Member Australasian Mine-Managers' Association. General Contents. —Introductory: Prospecting (Alluvial and General) Lode or Reef Prospecting—Genesiology of Gold—Auriferous Lodes—Drifts^ Gold Extraction— Lixiviation—Calcination—Motor Power and its Transmission —Company Formation — Mining Appliances and Methods — Australasian Mining Regulations.

"Practical from beginning to end . . . deals thoroughly with the Prospecting, Sinking, Crushing, and Extraction of gold." Brit. Australasian.

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Large 8vo. Handsome Cloth. With Illustrations. 12s. 6d. net. METALLURGICAL ANALYSIS & ASSAYING: A THREE YEARS' COURSE FOR STUDENTS OF SCHOOLS OF IVIINES. By W. a. MACLEOD, B.A., B.Sc, A.O.S.M. (N.Z.), Formerly Assist.-Director, Thames School of Mines (N.Z.), aad Lecturer in Cliemistry, University

of Tasmania ; Director of Queensland Government School of Mines, Charters Towers : And CHAS. WALKER, F.C.S.,

ormerly Assist.-Demonstrator in Chemistry, Sydney University : Lecturer n Chemistry and Metallurgy, Charters Towers School of Mines

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In Crown 8vo, Beautifully Illustrated with nearly 100 Microphotographs of Steel, &c. 7s. 6d. net. MICROSCOPIC ANALYSIS OF METALS. By FLORIS OSMOND & J. E. STEAD, F.R.S., F.LC. Contents. —Metallography considered as a method of Assay. — Micro- graphic Analysis of Carbon Steels. —Preparation of Specimens. —Polishing. —Constituents of Steel; Ferrite; Cementite; Pearlite; Sorbite; Martensite;

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A PRACTICAL TREATISE ON THE ART OF EXTRACTING METALS FROM THEIR ORES.

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At Press. Second Edition, Revised Throughout and JSnlarged. Re-set on Larger Page. With Valuable Bibliography, New Maps, Illustrations, dsc. PETROLEUM AND ITS PRODUCTS. R. T^TS.R.CrP'LCRlU TI5EJ5.TISE. By SIR BOVERTOTf REDWOOD, F.B.S.E., F.I.O., Assoo.R.C.S., Corr. of Hod. Mem. the Imperial Russian Technical Society : Mem. of the American Chemical

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STANDARD WORKS OF REFERENCE FOR Metallurgists, Mine-Owners, Assayers, Manufacturers, and aU interested in the development of the Metallurgical Industries.

EDITED BY Sir W. ROBERTS-AUSTEN, K.C.B., D.C.L., F.R.S.

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INTKODUCTION to the STUDY of METALLTJEGY. By the Editor. Fifth Edition. i8s. (Seep. 63.) GOLD (The Metallurgy of). By Thos. Kirke Rose, D.Sc, Assoc. R.S.M., F.C.S., Chemist and Assayer of the Royal Mint. Fifth Edition. 21s. (Seep. 63.)

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Will he Published at Short IntsruaU.

METALLURGICAL MACHINERY : the Application of Engineering to Metallurgical Problems. By Henry Charles Jenkins, Wh.Sc, Assoc.R-S.M., Assoc. M. Inst. C.E., of the Royal College of Science. (See p. 64). COPPER (The Metallurgy of). By Thos. C. Cloud, Assoc. R.S.M. • ALLOYS. By Edward T. Law, Assoc.R.S.M.

*^,* Other Volumes in Preparation.

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METALLURGICAL WORKS. 63

GRirriN'S METALLURGICAL SERIES.

Fifth Edition, thoroughly Revised and considerably Enlarged. Large 8vo, with numerous Illustrations and Micro-Photographic Plates of different varieties of Steel. i8s. An Introduction to the Study of

5ir W. ROBERTS-AUSTEN, K.C.B., D.C.L., F.R.S., A.R.S.M., Late Chemist and Assayer of the Royal Mint, and Professor of Metallurgy in the Royal College of Science. General Contents.—The Relation of Metallurgy to Chemistry. —Physical Properties of Metals.—Alloys. The Thermal Treatment of Metals. — Fuel and Thermal Measurements. —Materials and Products of Metallurgical Processes. — Furnaces.—Means of Supplying Air to Furnaces. —Thermo- Chemistry. —Typical Metallurgical Processes. —The Micro-Structure of Metals and Alloys. —Economic Considerations.

*' No English text-book at all approaches this in the completeness with which the most modem views on the subject are dealt with. Professor Austen's volume will be invaluable, not only to the student, but also to those whose knowledge of the art is far advanced." Chetnical News.

Fifth Edition, Kevised, Considerably Enlarged, and in part Re-written. With Frontispiece and numerous Illustrations. 21s. THE METALLURGY OF GOLD,

T. KIRKE ROSE, D.ScLond., Assoc.R.S.M., Chemist and Assayer of the Royal Mint.

General Contents.—The Properties of Gold and its Alloys.—Chemistry of the Compounds of Gold.— M-ode of Occurrence and Distribution of Gold.—Shallow Placer Deposits. —Deep Placer Deposits. —Quartz Crushing in the Stamp Battery. —Amalgam- ation in the Stamp Batterv.—Other Forms of Crushing and Amalgamating Machinery. —Concentration in Gold Mills.—Dry Crushing.—Ke-grinding.— Roasting.—Chlorination: The Plattner Process, The Barrel Process, The Vat-Solution Process.—The Cyanide Process.—Chemistry of the Cyanide Process.—Refining and Parting of Gold Bullion. —Assay of Gold Ores.—Assay oi Gold Bullion.—Statistics of Gold Production.—Biblio- graphy. —I NDEX. " AooMPRBHENSivE PKACTicAL TREATISE ou this important sub]6ct,"— TVie Times. '*The MOST COMPLETE description of the chlohination process which has yet been pub- lished."— J/inm? Journal. "Adapted for all who are interested in the Gold Mining Industry, being free from tech- nicalities as far as possible, but is more particularly of value to those engaged in the Industry." Cape Times.

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64 CHARLES ORIFFIN & CO.'S PUBLICATIONS.

O-BIPPIN'S METALIiITEaiCAL SERIES. Edited et SIR W. ROBERTS-AUSTEN, K.C.B., F.R.S., D.C.L.

In Large 8vo. Handsome Cloth. With Illustrations.

In Two Volumes, Each Complete in Itself and Sold Separately. THE METALLURGY OF LEAD AND SILVER. By H. F. COLLINS, Assoc.E.S.M., M.Inst.M.M. I>aict I.—LEAID: A Complete and Exhaustive Treatise on the Manufacture of Lead, with Sections on Smelting and Desilverisation, and Chapters on the Assay and Analysis of the Materials involved. Price i6s. Summary of Contents. —Sampling and Assaying Lead and Silver. —Properties and Compounds of Lead.—Lead Ores.—Lead Smelting.—Reverberatories.—Lead Smelting in Hearths.—The Hoasting of Lead Ores.—Blast Furnace Smelting; Principles, Practice, and Examples ; Products. —Flue Dust, its Composition, Collection and Treatment. Costs and Losses, Purchase of Ores. —Treatment of Zinc, Lead Sulphides, Desilverisation, Softening and Refining. —The Pattinson Process. —The Parkes Process.-Cupellation and Refining, &c., &c. "A THOROUGHLY SOUND and useful digest. May with evert coNFmENCE be recommended." Mining Journal.

I>art II.—SILVER. Comprising Details regarding the Sources and Treatment of Silver Ores, together with Descriptions of Plant, Machinery, and Processes of Manufacture, Refining of Bullion, Cost of Working, &c. Price 16s. Summary of Contents.—Properties of Silver and its Principal Compounds.—Silver res. —The Patio Process. —The Kazo, Fondon, Krohnke, and Tina Processes.—The Pan Process. —Roast Amalgamation.—Treatment of Tailings and Concentration. —Retorting, Melting, and Assaying —Chloridising-Roasting.-The Augustin, Claudet, and Zievvogel Processes. —The Hypo-Sulphite Leaching Process. —Refining. —Matte Smelting. —Pyritic Smelting. —Matte Smelting in Reverberatories. —Silver-Copper Smelting and Refining. Index. "The author has focussed A large amount of valuablk information into a convenient form. . . . The author has evidently considerable practical experience, and describes the various processes clearly and well. ' Mining Journal.

metalldrgYcal" machinery : The Application of Engineering to l\fletallurgiGal Problems. By henry CHARLES JENKINS, Wh.Sc, Assoc. R.S M., Assoc.M.Inst.C.E.

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GBIFFIN'S METALLTTRGICAL SERIES.

Second Edition, Revised. With Numerous Illustrations. Large 8vo. Handsome Cloth. '25s. net. With Additional Chapter on The Electric Smelting of Steel, THE METALLURGY OF STEEL, By F. W. HARBORD, Assoc.R.S.M., F.I.C., Consulting Metallurgist and Analytical Chemist to the Indian Government, Royal Indian SJngineering College, Coopers Hill. With 37 Plates, 280 Illustrations in the Text, and nearly 100 Micro- Sections of Steel, and a Section on THE MECHANICAL -TREATMENT OP STEEL. By J. W. HALL, A.M.Inst. C.E. Abeidged Contents.—Ttie Plant, Machiaery, Methods and Chemistrv of the Bessemer and of tne Open Hearth Processes (Acid and Basic I. —The Mecuaaical Treatment of Steel comprising Mill Practice, Plant aad Machinery. — The Influence of Metalloids, Heat Treatment, Special Steels, Microstructure, Testing, and Speciflcations. "A work which we venture to commend as an invaluable compendium of information upon the metallurgy of steel." Iron and Coat Trades' Review. The Engineer says, at the conclusion of a review of this hook :—" We cannot conclude without earnestly recommending all who may be interested as makers or users of steel, which practically means the whole of the engineering profession, to make themselves acquainted with it as speedily as possible, and this may be the more easily done as the published price, considering the size of the book, is extremely moderate."

Second Edition, Revised. Price 16s. THE METALLURGY OF IROM. By THOMAS TURNER, Assoc.R.S.M., F.I.C., Professor of Metallurgy in the University of Birmingham. In Large 8vo, Handsome Cloth, With Numerous Illustrations (many from Photographs).

General Contents. —Early History of Iron.—Modern History of Iron. —The Age of Steel. —Chief Iron Ores. —Preparation of Iron Ores —The Blast Furnace.—The Air used in the Blast Furnace. —Keactions of the Blast Furnace. —The Fuel used in the Blast Furnace, Slaga and Fuxes of Iron Smelting.- Properties of Cast Iron.— Foundry Practice. —Wrought Iron. —Indirect Production of Wrought Iron.—The Puddling Process.-Further Treatment of Wrought Iron. - Corrosion of Iron and Steel. ** A MOST VALUABLE SUMMARY of knowledge relating to every method and stage in the manufacture of cast and wrought iron . . . rich in chemical details. . . , Exhaustive and thoroughly up-to-date."—Bulletin of the American Iron and Steel Association, " This \s A DELIGHTFUL BOOK, giviug, as it does, reliable information on a subject becoming every day more elaborate." Colliery Guardian. ** A thoroughly useful book, which brings the subject up to date. Of GREAT VALUE to those engaged in the iron industry." Mining Journal.

*^^* For Professor Turner's Lectures on Iron- Founding,, see pa^^^e 68.

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«6 CHARLES GRIFFIN & CO.'S PUBLICATIONS. A TEXT-BOOK OF ASSAYING: For the use of Students, Mine Managers, Assayers, do.

By J. J. BERINGER, F.I.C, F.C.S., Public Analyst for, and Lecturer to the Mining Association of, Cornwall. And C. BERINGER, F.C.S., Late Chief Assayer to the Rio Tinto Copper Company, London, With numerous Tables and Illustrations. Crown 8vo. Cloth, los. 6d, Ninth Edition.

Ghnbral Contents. — Part I. — Introductory; Manipulation: Sampling; Drying; Calculation of Results—Laboratory-books and Reports. Methods: Dry Gravi- metric; Wet Gravimetric— Volumetric Assays: Titrometric, Colorimetric, Gasoraetric Weighing and Measuring— Reagents— Formulas, Equations, &c.— Specific Gravity.

Part II. Metals : Detection and Assay of Silver, Gold, Platinum, Mercury, Copper, Lead, Thallium, Bismuth, Antimony, Iron, Nickel, Cobalt, Zinc, Cadmium, Tin, Tungsten, Titanium, Manganese, Chromium, &:c. —Earths, Alkalies.

Part III. Non-Metals : Oxygen and Oxides; The Halogens—Sulphur and Sul- phates—Arsenic, Phosphorus, Nitrogen—Silicon, Carbon, Boron—Useful Tables. "A REALLY meritorious vifORK, that may be safely depended upon either for systematic instruction or for reference." Nature. "This work is one of the best of its kind." Enshieer.

Third Edition, Revised. Handsome Cloth. With Numerotcs Illustrations. 6s. A TEXT-BOOK OF ELEMENTARY METALLURGY. Including the Author's Pkactical Laeokatoky ConKSE. By a. HUMBOLDT SEXTON, F.I.C, F.O.S., Professor of Metallurgy in the Glasgow and West of Scotland Technical College. GENERAL CONTENTS.—Introduction.—Properties of the Metals.—Combustion. — Fuels. — Refractory Materials. — Furnaces. — Occurrence of the Metals in Nature. Preparation of the Ore for the Smelter. —Metallurgical Processes.—Iron. —Steel. <3opper. —Lead.— Zinc and Tin. —Silver. — Gold. — Mercury. — Alloys. — Applications of Electricity to Metallurgy. Laboeatokt Course. " Just the kind of work for Students commencing the study of Metal- lurgy, or for Engineering Students." Practical Engineer, "Excellently got-up and well-arranged."— Cliemical Trade Journal.

In Large 8vo. Handsome Cloth. Price 4s. TABLES FOR QUANTITATIYE METALLURGICAL ANALYSIS. FOR LABORATORY USE. ON THE PRINCIPLE OF "GROUP" SEPARATIONS. By J. JAMES MORGAN, F.O.S., M.S.C.I. " The Author may be oongratulated on the way his work haa been carried out."— The Engineer. "Will COMMEND ITSELF highly in Laboratory Practice. Its cleaeness and precision •mark the book out as a bighly nseful one." Mining Journal.

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ELEGTRO-METALLURQY, ETG. 67

Second Edition, Revised, Enlarged, and in part Re-written. With Additional Sections on Modern Theories of Electrolysis Costs, &c. Price 10s. 6d. A TREATISE ON ELECTRO-METALLURGY: Embracing the Application of Electrolysis to the Plating, Depositing, Smelting, and Refining of various Metals, and to the Repro- duction of Printing Surfaces and Art-Work, &o, EY WALTER G. MCMILLAN, F.I.C., F.C.S., Secretary to the Institutimi of Electrical Engineers ; late Lecturer in Metallurgy at Mason College^ Binningham,, With numerous Illustrations. Large Crown 8vo. Cloth. " This excellent treatise, . . . one of the best and most complete manuals hitherto published on Electro-Metallurgy." Electrical Review. " This work will be a standard."—Jeweller. " Any metallurgical process which reduces the cost of production must of necessity prove of great commercial importance. . . . We recommend this manual to all who are interested in the practical APPLICATION of electrolytic processes." Nature.

Second Edition, Thoroughly Revised and Enlarged. In large 8vo. With Numerous Illustrations and Three Folding- Plates. 21s. net. ELECTRIC SlELTIia & EEEira&: A Practical Manual of the Extraction and Treatment of Metals by Electrical Methods. Being the " Elektro-Metallukoie " of Dr. W. BORCHERS. Translated from the Latest German Edition by WALTER G. MCMILLAN, F.I.C, F.O.S. CONTENTS.

Part I. Alkalies and Alkaline Earth Metals : Magnesium^ Lithium, Beryllium, Sodium, Potassium, Calcium, Strontium, Barium, the Carbides of the Alkaline Earth Metals. Part II. The Earth Metals: Aluminium, Cerium, Lanthanum, Didymium.

Part III. The Heavy Metals : Copper, Silver, Gold, Zinc and Cad- mium, Mercury, Tin, Lead, Bismuth, Antimony, Chromium, Molybdenum, Tungsten, Uranium, Manganese, Iron, Nickel, and Cobalt, the Platinum Group.

" Comprehensive and adthoeitative . . . not only full of valuable ihfok- MATION, but give'* evidence of a thorough insight into the technical value and possibilities of all the methods discussed." The Electrician. " Dr. BoRCHERS' well-known work . . . must OF necessity be acquired by every one interested in the subject. Excellently put into English with addition^ matter by Mr. M'^Millan."—nature. " Will be of GREAT SERVIOK to the practical man and the Student." Electric Smelting.

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'68 CHARLES GRIFFIN

In Large ito, Librari/ Style. Beautifully Illustrated with SO Plates, many in Colours, and Figures in the Text. 23. net. PRECIOUS94 STONES:£2, Their Properties, Oecurrenees, and Uses. A Treatise for Dealers, Manufacturers, Jewellers, and for all Collectors and others interested in Gems. By Dr. MAX BAUER, Professor in the University of Marburg, Translated by L. J. SPENCER, M.A. (Cantab.), F.G.S. GrENERAL Contents. —General Properties of Gems: Their Natural Characters, Occurrence, Application, and Uses.— Detailed Description of Particular Gems: The

Diamond, liubies, Sapphires ; Emeralds, Tourmalines, and Opals ; Felspars, Amphiboles, Malachite. —Non-mineral Gems: Amber, &c.— Optical Features, Transparency, Trans- lucency, Opacity, Kefraction and Dispersion, &c.—Appendix: Pearls; Coral. " The plates are remarkable for their beauty, delicacy, and truthfulness. A glance at

them alone i-^ a lesson on precious stones, whilst the perusal of the work itself should add a new interest to any casket of jewels or cabinet of gems, or even to a jewellers' window." Athenmum. " The work is one to be recommended to every jeweller." rhe Jeicellers' Circular.

In Large Grown Svo, With Numerotis Illustrations. 8a. 6d.

The Art of the Goldsmith and Jeweller A Manual on the Manipulation of Gold and the Manu- facture of Personal Ornaments. By THOS. B. WIGLEY, Eeadmaster of the Jewellers and Silversmiths' Association Technical School, Birmingham. ASSISTED BY J. H. STANSBIE, B.Sc. (LoND.), F.I.O., Lecturer at the Birmingham Municipal Technical School. General Contents.—Introduction. —The Ancient Goldsmith's Art. — Metallurgy of Gold.—Prices,

Extra Crown Suo. With 48 Illustrations. 3s. 6cZ. net. LECTURES ON IRON-FOUNDING. By THOMAS TURNER, M.Sc, A.R.S.M., F.I.C., Professor of Metallurgy in the University of Binningham

Contents.-Varieties of Iron and Steel.—Application oft Cast Iron.—History.—Pro- duction. — Iron Ores. — Composition. — The Blast Furnace.— Materials. — Reactions. Grading Pig Iron. — Carbon, Silicon, Sulphur, Phosphorus, Manganese, Ahuninium, Arsenic, Copper, and Titanium.—The Foundry. —General Arrangement.—Re-melting Cast Iron. —The Cupola. —Fuel Used. — Changes due to Re-melting. — Moulds and Moulding.—Foundry Ladles.—Pouring and Pouring Temperature. —Common Troubles.— Influence of Shape and Size on Strength of Casting.—Tests. " Ironfounders will find much information in the book."—Zrtm Trade Circular {Ryland's).

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Griffin's Chemical and Technological Publications. — — — — —

70 CHARLES OEIFFIN

Third Edition, Revised, Enlarged, and Re-issued. Price 6s. net. A SHORT MANUAL OF INORGANIC CHEMISTRY.

BY A. DUPRE, Ph.D., F.R.S.,

AND WILSON HAKE, Ph.D., F.I.O., F.C.S., Of the Westminster Hospital Medical School. " A well-written, clear and accurate Elementary Manual of Inorganic Chemistry. . . We agree heartily with the system adopted by Drs. Duprd and Hake- Will makb Experi- mental Work trkblv interesting because intelligible. " Saturday Review. ''There is no question that, given the perfect grounding of the Student in his Saence, the remainder comes afterwards to him in a manner much more simple and easily acquired. The work is an example of the advantages of the Systematic Treatment of a Science over the fragmentary style so generally followed. By a long way the best of tho small Manuals for Students." Analyst.

LABORATORY HANDBOOKS BY A. HUMBOLDT SEXTON, Professor of Metallurgy in the Glasgow and West of Scotland Technical College,

OUTLINES OF QUANTITATIVE ANALYSIS. FOR THE USE OF STUDENTS.

With Illustrations. Fourth Edition. Crown 8vo, Cloth, 3a. " A COMPACT lABOEATORY GUIDE for beginners was wanted, and the want has been wkll supplied. ... A good and nsefuJ book," Lancet.

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With Illustrations. Fourth Edition, Revised. Crown 8vo, Cloth, 3s. 6d, '* The work of a thoroughly practical chemist." British Medical Journal. " Compiled with great care, and wUl supply a want." Journal of Education. ELEMENTARY METALLURGY: Including the Author's Practical Laboratory Course. With many Illustrations. . [See p. 66;

Third Edition, Revised. Crown 8vo. Cloth, 6s. ** Just the kind of work for students commencing the study of metallurgy." Pradicdi Engineer.

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CHEMISTRY AND TECHNOLOOT. 71

"The authors have stJCCsuDED beyond all expectations, and have produced a work which ahouldgive fresh powbr to the Engineer and Manufacturer."— rAe Times.- In Two Vols., Large 8vo. With Illustrations. Sold Separately. CHEMISTRY FOR ENGINEERS AND MANUFACTURERS. A PRACTICAL TEXT-BOOK. BY BERTRAM BLOUNT, F.I.C., & A. G. BLOXAM, F.I.O. "srot.xjivrE: i. r»x'ice xos. ed. CHEMISTRY OP ENGINEERING, BUILDING, AND METALLURGY. General Coretenfe.—INTRODUCTION—Chemistry of the Chief Materials of Construction—Sources of Energy—Chemistry of Steam-raising—Chemis- try of Lubrication and Lubricants—Metallurgical Processes used in the Winning and Manufacture of Metals. 'U-OIL.UIVIE: XX. Px-lco X6s.

Second Edition, Thoroughly Revised. Illustrated. I63. THE CHEMISTRY OF MANUFACTURING PROCESSES. General Contents. —Sulphuric Acid Manufacture— Altall, &c. -Destructive Distillation —Artificial Manure— Petroleum—Lime and Cement—Clay and Glass — Sugar and Starch — Brewing and Distilling — Oils, Resins, and Varnishes—Soap and Caudles — Textiles and Bleaching — Colouring Matters, Dyeing, and Printing — Paper and Pasteboard — Pigments and Paints — Leather, Glue, and Size — Explosives and Matches — Minor Manufactures. " Certainly a good and USEPDI. book, constituting a PRAcriCAL guide for students by affording a clear conception of the numerous processes as a whole." Chamical Trade Journal.

Second Edition. In Large 8vo. Handsome Cloth. With 800 pages and 154 Illustrations. 25s. net. OILS, FATS, BUTTERS, AND WAXES THEIR PREPARATION AND PROPERTIES, AND MANUFACTURE THERE- FROM OF CANDLES, SOAPS, AND OTHER PRODUCTS. By C. R. alder WRIGHT, D.Sc, F.R.S.,

Late Lecturer on Chemistry, St. Marv's Hospital Medical School ; Examiner in " Soap " to the City and Guilds of Lonaon Institute. Thoroughly Revised, Enlarged, and in Part Rewritten By C. AINSWORTH MITCHELL, M.A., F.LC. — *' Will be found absolutely indispensable." The Analyst. "Will rank as the Standard English Authority on Oils and Fats for many years to come." Indust-ries and Iron.

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72 OHARLES OBIFFIN & GO.'S PUBLICATIONS.

Fifth Edition, Thoroughly Revised, Greatly Enlarged and Re-written. With additionalFOODS;Tables, Plates, and Illustrations. 21s. THEIR COMPOSITION AND ANALYSIS. By a. WYNTER BLYTH, M.E.C.S., F.IC, F.C.S., BarriEter-at-Law, Public Analyst for the County of Devon, and Medical Of&cer of Health for St. Maryiebone. And M. WYNTER BLYTH, B.A., B.Sc., F.C.S.

General Contents. — History of Adulteration. ^— Legislation. — Ap- paratus. —" Ash."—Sugar. — Confectionery. — Honey. — Treacle. — Jams and Preserved Fruits. — Starches. — Wheaten-Flour. — Bread. — Oats. Barley. — Rye. — Rice. — Maize. — Millet. — Potatoes. — Peas. — Lentils. — Beans. — Milk. — Cream. — Butter. — Oleo-Margarine. — Cheese. — Lard. — Tea. — Coffee. — Cocoa and Chocolate. — Aleohol. — Brandy. — Rum. — Whisky. —Gin. —Arrack. —liqueurs. — Absinthe. — Yeast. — Beer. —Wine. — Vinegar. — Lemon and Lime Juice. — Mustard. — Pepper. — Sweet and Bitter Almonds. —Annatto. — Olive Oil. —Water Analysis.—Appendix Adulteration Acts, &c. " Simply INDISPENSABLE in the Analyst's laboratory." The Lancet. "A new edition of Mr. Wynter Blyth'a Standard work, eneiched with all the becekt DISCOVEBIES AND IMPROVEMENTS, Will bs accoptcd as a boon." Chemical News.

Fourth Edition. In Large 8vo, Cloth, with Tables and Illnstrations. POISONS:Thoroughly Revised. THEIR EFFECTS AND DETECTION. By a. wynter BLYTH, M.R.C.S., F.I.C., F.O.S., Barrister-at-Law, Poblic Analyst for the Connty of Devon, and Medical OfBcer of Health for St Maryiebone. GENERAi CONTENTS. I. —Historical Introduction. II. —Classification—Statistics—Connection between Toxic Action and Chemical Composition—Life Tests—General Method of Procedure—The Spectroscope—Examination of Blood and Blood Stsiins. in. —Poisonous Gases. IV. —Acids and Alkalies. V.—More or less Volatile Poisonous Substances. VI. —Alkaloids and Poisonous Vegetable Principles. VII. —Poisons derived from Living or Dead Animal Substances. VIII. —The Oxalic Acid Group. IX. —Inorganic Poisons.

Appendix : Treatment, by Antidotes or otherwise, of Cases of Poisoning.

" Undoubtedly the most complete woek on Toxicology in our language." The .Analyst ton the Third EdUion). " As a pbactical quide, we know no bettee work." 2'he Lancet (on the Third Edition). •»* In the Thied Edition, Enlarged aud partly Re-written, New Analytical Methods have been Introduced, and the Cadaveeic Alkaloids, or Ptomaines, bodies playing so great a oart in Food-polsoning and in the Manifestations of Disease, have received special attention.

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CHEMISTRY AND TECHNOLOOY. 73 DAIRYWith Numerous Tables,CHEMISTRYand 22 Illustrations. i6s. ;FOR DAIRY MANAGERS, CHEMISTS, AND ANALYSTS A Practical Handbook for Dairy Chemists and others having Control of Dairies. By H. droop RICHMOND, F.I.C., CHEMIST TO THE AYLESBURY DAIRY COMPANY. Contents. — I. Introductory. —The Constituents of Milk. IT. The Analysis o\

Milk. III. Normal Milk : its Adulterations and Alterations, and their Detection. 'IV. The Chemical Control of the Dairy. V, Biological and Sanitary Matters. VI. Butter. VII. Other Milk Products. VIII. The Milk of Mammals other than the Cow.—Appendices. —Tables, —Index. *'. . . In our opinion the book is the best contribution OS the subject that HAS YET APPEARED in the English language." Lancet.

Fully Illustrated. With Photographs of Various Breeds of Cattle, &c. 6 s ix^t MILK: ITS PRODUCTION & USES. With Chapters on Dairy Farming, The Diseases of Cattle, and on the Hygiene and Control of Supplies. By EDWARD F. WILLOUGHBY, M.D. (Lond-X D.P.H. (Lend, and Canib.), Inspector of Farms and General Scientific Adviser to Welford and Sons, Ltd. "A good investment to those in the least interested in dairying. Excellently bound printed on good paper, and well illustrated, running to 259 pages, the purchaser gets at the price of a novel a work which will stand good as a work of reference for some years to come."—Agricult. Gazette. We cordially recommend it to everyone who has anything at all to do with milk."— Dairy World.

In Crown 8vo, Fully Illustrated. 2s. 6d. net. DAIRYTHE LABORATORYANALYSIS.BOOK OF By H. droop RICHMOND, F.I.C., Analyst to the Aylesbury Dairy Co., Ltd. Contents. —Composition of Milk and its Products. —Analysis of Milk. Analysis of Liquid Products. —Application of Analysis to the Solution of Problems. —The Analysis of Butter. —Analysis of Cheese. —Tables for Calcu- lation. —Standard Solutions. Index.

" Without doubt the best contribution to the literature of its subject that has ever been written." Medical Times.

In Large 8vo. Handsome Cloth. AGRICULTURAL CHEMISTRY AND ANALYSIS A PRACTICAL HANDBOOK FOR THE USE OF AGRICULTURAL STUDENTS. By J. M. H. MUNRO, D.Sc, F.I.C., F.C.S., Professor of Chemistry, Downton College of Agriculture. [/n Preparation,

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Crown 8vo, Handsome Cloth. Fully Illustrated. los. 6d. FLESH FOODS: With Methods for their Chemical, Microscopical, and Bacterio- logical Examination. A Practical Handbook for Medical Men, Analysts, Inspectors and others. By C. AINSWORTH MITCHELL, B.A.(Oxon),

Fellow of the Institute of Chemistry ; Member of Council, Society of Public Ajialysts.

With Numerous Tables, Illustrations, arid u, Coloured Plate, Contents. —Structure and Chemical Composition of Muscular Fibre. —oi Connective Tissue, and Blood. —The Flesh of Different Animals. —The Examina- tion of Flesh. —Methods of Examining Animal Fat. —The Preservation of Flesh. —Composition and Analysis of Sausages. — Proteids of Flesh. —Meat Extracts and Flesh Peptones. —The Cooking of Flesh. —Poisonous Flesh. —The Animal Para- sites of Flesh. —The Bacteriological Examination of Flesh.—The Extraction and Separation of Ptomaines. Index.

" A compilation which will be most useful for the class for whom it is intended." Aikenaum. " A book which NO one whose duties involve considerations of food supply CAN AFFORD TO BH WrrHOUT." —Municipal Journal.

In Large 8vo. Handsome Cloth. With numerDus Illustrations, Each Volume Complete in Itself, and Sold Separately. TECHNICAL MYCOLOGY: THE UTILISATION OF MICRO-ORGANISMS IN THE ARTS AND MANUFACTURES. A Practical Handbook on hermentation and Fermentative Processes for the Use of Brewers and Distillers, Analysts, Technical and Agricultural Chemists, and all interested in the Industries dependent on Fermentation. By Dk. FRANZ LAFAR, Professor of Fermentation-Physiology and 'Bacteriology in the Technical High School, Vienna. With an Introduction by Dk. EMIL CHR. HANSEN, Principal of the Carlaberg Laboratory, Copenhagen. Translated by CHARLES T. C. SALTER. Vol. I.—SCHIZOMYCBTIC FERMKNTATION, 15s. Including the Theory of Fermentation, the Principles of Sterilization, and Pure Ctdture Processes. Vol. II., Part I.—EUMYCETIC FERMENTATION. 7s, 6d. The Morphology, Chemistry Physiology, and Fermentative Processes of the Eumycetes, Zygomycetes, and Saccharomycetes.

"The first work of the kind which can lay claim to completeness in the treatment of a faacinating subject. The plan is admirable, the cIassiflc#iou simple, the style is good, and the tendency of the whole volume is to convey sure information to the reader." Lancet %* The publishers trust that before long they will be able to present EnpKsh readers with the whole of the second volume, arrangements having been concluded whereby, upon its appearance in Germany, the English translation will be at once put in hand. This is now being done with Part I., which will be- issued shortly, and wtich will be followed by lie two final parts.

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A Text-book on the Chemistry and Physics of Fermentatiue Changes. By carl OPPENHEIMER, Ph.D., M. D., Of the Phjsiological Institute at Erlangen. Translated feom the German by a AINSWORTH MITCHELL, B.A., F.LC, F.C.S. Abridged Contents.—Introductioa.— Definition. —Chemical Nature of Ferments.— Influence of External Factors.—Mode of Action.—Physiological Action. — Secretion.— ImportanceofFermentsto Vital Action. —Proteolytic Ferments. —Trypsin. — Bacteriolytic and Hsemolytic Ferments.—Vegetable Ferments.—CoagulatingFerments.— Saccharifying Ferments. — Diastases. — Polysaccharides. — Enzymes. — Ferments which decompose Glu cos ides.— Hydroly tic Ferments.—Lactic Acid Fermentation.— Alcoholic Fermenta- tion.—Biology of Alcoholic Fermentation.-Oxydases.—Oxidising Fermentation.—Bibli- ography. —I N DEX. " Such a veritable multnm in parvo has never yet appeared. The author has set himself the task of writing a work on Ferments that should embrace human erudition on the subject "^Brewers' Journal-

Crown 8vo. Handsome Cloth. [Companion Volume to "FERMENTS," by the same Author.'\ TOXINES AND ANTITOXINES. By OARL OPPENHEIMER, Ph.D., M.D., Of the Physiological Institute at Erlangen. Translated from the German by C. AINSWORTH MITCHELL, M.A., F.LC, F.C.S. With Notes and Additions by the Author, since the publication of the German Edition. Deals with the theory of Bacterial, Animal, and Vegetable Tozines, such as 'lubercvZin, Ricin, Cobra Poison, dec. Bacteriologists, Medical Students, and Scientific Workers will find this book most valuable.

Third Edition. In Handsome Cloth. Fully Illustrated. PRINCIPLES AND PRACTICE OF BREWING. FOR THE USE OF STUDENTS AND PRACTICAL MEN. By WALTER J. SYKES. Revised by ARTHUR R. LING, F.LC, F.C.S., Editor of the Journal of the Institute of Brewing.

In Crown 8vo. Handsome Cloth. A PRACTICAL LABORATORY HANDBOOK ON THE BACTERIOLOGY OF BREWING. By WALTER A. RILEY, F.C.S. Abridged Contents. — Laboratory Handbook and Apparatus. — Sterilisation. — Nutritive Liquids. — Microscope, Beageats, &c.— Methods of Analysis. — Practical Methods, including the use of '*Brettanomyces," Cider and Wine Fermentations- Determining E-aces of Yeasts, &c.—Practical Notes on Yeast.

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76 CHARLES GRIFFIN

Second Edition, Revised and Enlarged. With Tables, Illustrations in the Text, and 37 Lithographic Plates. Medium 8vo. Handsome Cloth. 30s. SEWAGE DISPOSAL WORKS: A Guide to the Construction of Works for the Prevention of the Pollution by Sewage of Rivers and Estuaries. By W. SANTO CRIMP, M.Inst.C.E., F.G.S., Late Assistant-Engineer, London County CounciL "Probably the most complete and rest treatise on the subject which has appeared- in our language." Edinburgh MedicalJournal.

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A Manual for the Use of Manufacturers, Inspectors, Medical Officers of Health, Engineers, and Others. By WILLIAM NICHOLSON, Chie Smoke Inspector to the Sheflaeld Corporation. wONTENTS.— Introduction. — General Legislation against the Smoke Nuisance.- Local Legislation. —Foreign Laws. —Smoke Abatement.—Smoke from Boilers, l^urnaces, and Kilns. —Private Dwelling- House Smoke. — Chimneys and their Construction. Smoke Preventers and Fuel Savers. — Waste Gases from Metallurgical I\irnaces. — Summary and Conclusions. Index. " This practical book on smoke abatement ... is likely to meet a long-felt

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VoLuiviE I. Price 7s. 6cl. net. V, II.—Ready Shortly- THE CHEMISTRY OF GAS IVtANXJFACTXJRE : A Hand-Book on the Production, Purification, and Testing of Illuminating Gas, and the Assay of the Bye-Products of Gas Manufacture. By W. J. ATKINSON BTJTTERFIELD, M.A., F.I.C., F.O.S., Pormerly Head Chemist, Gas Works, Beckfcon, London, E. " The BEST WOEK of its kind which we have ever had the pleasure of re- viewing." Journal of Gas LightiTig.

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THE PRINCIPLES OF ITS GENERATION AND USE. By F. H. LEEDS, F.I.C., F.C.S., Member of the Society of Public Analysts and of the Acetylene Association; And W. J. ATKINSON BUTTERFIELD, M.A., F.I.C., F.CS., Consulting Chemist, Author of "The Chemistry of Gas Manufacture." " Brimful of information."—CAejJi. Trade Jmtrnal. "We can thoroughly recommend the book to the manufacturer as a reliable work of reference, to the user as supplying valuable hints on apparatus and methods procedure, and to the student as a safe and certain guide." Acetylene.

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Twelfth Edition, Revised and Enlarged. Price 6s. PRACTICAL SANITATION: A HAND-BOOK FOR SANITARY INSPECTORS AND OTHERS INTERESTED IN SANITATION. By GEORGE REID, M.D., D.P.H., Felunu^ Mem. Council, and Examiner, Sanitary Institute of Great Britain, and Medical Officer to the Staffordshire County Council. TUnttb an appenaiE on Sanltarg Xaw. By HERBERT MANLEY, M.A., M.B., D.P.H., Medical 0_fficer ofHealth for th£ County Borough of West Bronvwich. Generai. Contents. —Introduction — Water Supply: Drinking Water, PoUution of Water—Ventilation and Wanning — Principles of Sewage Removal — Details of Drainage Refuse Removal and Disposal Sanitary ; — and Insanitary Work and Appliances—Details of Plumbers Work—House

Construction — Infection and Disinfection — Food, Inspection of ; Charac-

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Appendix : Sanitary Law ; Model Bye-Laws, &c.

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Borough Engineer and Surveyor, FuUiam ; late Borough Engineer, Bacup, Lanes. aENERAL CONTENTS. Intxoduction. —Hydraulics. —Velocity of Water in Pipes. — Earth Pressiu-es and Retaining Walls. —Powers. — House Drainage.- Land Drainage. —Sewers. —Separate System. —Sewage Pumping. —Sewer Ventilation.—Drainage Areas. — Sewers, Manholes, &c. —Trade Refuse. Sewage Disposal Works.—Bacteriolysis.— Sludge Dispos^— Construction and Cleansing of Sewers. —Refuse DisposaL —Chimneys and Foundations. " The volume bristles with i Qformation which will be greedily read by those in need of assistance. The book Is one that ou^ht to be on tlie boolcshelves of EVERY PRACTICAL ENGINEER,"—5a ni/tzry yournat, "A VERITABLE POCKET COMPENDIUM of Sanitary Engineering, ... A work which may, (n many respects, be considered as COMPLETE . . COMMENDABLY CAUTIOUS INTERESTING . SUGGESTIVE,"— /"w^/ir Health Engineer,

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In T%vo Volumes, each complete in itself. PHYSICO-CHEMICAL TABLES FOR THE USE OF ANALYSTS, PHYSICISTS, CHEMICAL MANUFACTURERS AND SCIENTIFIC CHEMISTS.

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Third Edition, Revised and Enlarged. With Illustrations. 12s. 6d. Painters' Colours, Oils, & Varnishes: A PRACTICAIi MANUAIi. By GEORGE H. HURST, F.C.S.,

Member of the Society of Chemical I ndustry ; Lecturer on the Technology of Painters' Colours, Oils, and Varnishes, the Municipal Technical School, Manchester. General Contents. —Introductory The Composition, Manufacture, Assay, and Analysis of Pigments, White, Red, Yellow and Orange, Green,. Blue, Brown, and Black Lakes—Colour and Paint Machinery— Paint Vehicles- (Oils, Turpentine, &c,, &c.)—Driers Varnishes. '* A THOROUGHLY PRACTICAL book, . . . the ONLY English work that satisfactorily treats of the manufacture of oils, colours, and pigments." Ckenticai Trades' Joumal- %* For Mr. Hurst's Garment Dyeing and Cleaning, see p. 84.

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CHEMISTRY AND TECHNOLOGY. 8r

In Large 8vo. Handsome Cloth. With 4 Plates and Several Illustrations. i6s. net. THE CHEMISTRY OF INDIA RUBBER. A Treatise on the Nature of India Rubber, its Chemical and Physical Examination, and the Determination and Valuation of India Rubber Substitutes. Including the Outlines of a Theory on Vulcanisation. By carl otto WEBER, Ph.D. " Replete with scientific and also with technical interest. . . . The section on physical properties isacompleter^J7f?«eof every thing known on the subject." India-rubber Journal.

In Large Crown 8vo. Fully Illustrated. 5s. net. GI-XJE, CirEIL..H.TINE, AND THEIR ALLIED PRODUCTS, A Practical Handbook for the Manufacturer, Agriculturist, and Student of Technology. By THOMAS LAMBERT, Analytical and Technical Chemist. Contents. — Historical. Glue. —Gelatine. — Size and Isinglass.— Treatment of Efflu- ents produced in Glue and Gelatine Making. — Liquid and other Glues, Cements, &c. — Uses of Glue and Gelatine. — Residual Products. —Analysis of R.aw and Finished Products.— Appendix.— Index. PAPERIn Large Crown 8vo,TECHNOLOGY;Handsome Cloth. Fully Illustrated. AN ELEMENTARY MANUAL ON THE MANUFACTURE, PHYSICAL QUALITIES, AND CHEMICAL CONSTITUENTS OF PAPER AND OF PAPERMAKING FIBRES. With Selected Tables for Stationers, Publishers, and Others. By R. W. SINDALL, F.C.S.

Contents.— Introduction.—Technical Difficulties relating to Paper. —The Manufacture of Rag Paper, Hand-made, Machine-made ; Esparto Papers ; Chemical Wood Pulp ; Me- chanical Wood Pulp ; Wood Pulp Papers ; Art Papers; Hemp, Jute, and other Papers. The Physical Qualities of Paper: Weight, Thickness, Strength, Elasticity, &c. —The Chemical Constituents of Paper: Clay, Pearl Hardening, Gelatine, Casein, Rosin, Alum, Starch, Pigments, Aniline Dyes, &c.—— Chemical Analysis of Paper. —Microscopical Analy- sis. — Conditions Affecting Quality. "C.B.S. Units."— Vegetable Fibres used in Paper- making. — Chemical and Physical Characteristics of Fibres. —Cellulose. —Statistics relating to Paper. —Tables. — Bibliography. — Index.

In Large 8vo, Handsome Cloth. With Plates and Illustrations. 7s. 6d. net THE MANUFACTURE OF INK. A Handbook of the Production and Properties of Printing, Writing, and Copying Inks. By C. a. MITCHELL, M.A., F.LC, and T. C. HEPWORTH. General Contents.—Historical.— Inks and their Manuracture. —Writing Inks. — Carbon and Carbonaceous Inks. —Tannin Materials for Ink.— Nature of Inks. —Manufacture of Iron Gall Ink. — Logwood, Vanadium, and Aniline Black Inks. — Coloured Inks.— Examination of Writing Inks. — Printing" Inks. — Early Methods of Manufacture.— Manufacture o( Varnish Inks. —Preparation and Incorporation of the Pigment —Coloured Printing Inks.—Copying Inks. Marking Inks.— Natural Vegetable Inks.— Safety Inks and Papers. — Sympathetic Inks. — Ink Powders and Tablets. — Appendices. — Patent Specifications, &c. ' ' Thoroughly well arranged . • and of a genuinely practical order." British Printer.

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«2 GHARLES QRIFFIN xjsTisiE:s.

Second Edition, Thoroughly Revised Tlirouqhout. In Two Large Volumes. Handsome Cloth. A MANUAL OF DYEING: fOR THE USE OF PRACTICAL DYERS, MANUFACTURERS, STUDENTS, AND ALL INTERESTED IN THE ART OF DYEING. BY E. KNECHT, Ph.D., F.I.C., CHR. RAWSON, F.I.C., F.C.S., Head of the Chemiatry and Dyeing Department ol Late Head of the Chemiatry and Dyeing Department the Technical School, Manchester; Editor of "The of the Technical College, Bradford ; Member Jotunnl of the Society of Dyers and Colourists;" Council of the Society of Dyers and Coloarists; And RICHARD LOEWENTHAL, Ph.D. Gbneeal Contents. —Chemical Technology of the Textile Fabrics Water —Washing and Bleaching — Acids, Alkalies, Mordants — Natural Colouring Matters —Artificial Organic Colouring Matters — Mineral Colours —Machinery used in Dyeing—Tinctorial Properties of Colouring Matters

Analysis and Valuation of Materials used in Dyeing, &c. , &o. " Thia authoritative and exhaustive work the most complete we have yet seen on the subject." Textile Manufacturer.

In Large Svo, Handsome Cloth. Pp. i-xv + Iflo. 16s. net. THE SYNTHETIC DYESTUFFS, AND THE INTERMEDIATE PRODUCTS FROM WHICH THEY ARE DERIVED. By JOHN CANNELL CAIN, D.Sc. (Manchester and Tubingen), Technical Cliemist, And .JOCELYN FIELD THORPE, Ph.D. (Heidelberg), Lecturer on Colouring Matters in the Victoria University of JIanchester.

Part I. Theoretical. Part II. Practical. Part III. Analytical. " We have no hesitation in describing this treatise as one of the most valuable books

that has appeared. . . . Will give an impetus to the study of Organic Chemistry generally." Chemical Trade Journal.

**An excellent result of theoretical knowledge and practical experience, and is a, valuable addition to technical literature." Dyer.

Companion Volume to Knecht

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THE TEXTILE INDUSTRIES. 83 Large 8vo. Profusely Illustrated with Plates and Figures in the Text. 16s. net. THE SPINNING AND TWISTING OF LONG VEGETABLE FIBRES (FLAX, HEIVIP, JUTE, TOW, & RAIVIIE). A Practical Manual of the most Modern Methods as applied to the Hackling, Cardina Preparing, Spinning, and Twisting of the Long Vegetable Fibres of Commerce. Bt HERBERT R. CARTER, Belfast and Lille. General Contents.—Long Vegetable Fibres of Commerce.—Rise and Gro^vth the Spinnnig of Industry.—Raw Fibre Markets.—Purchasing Saw Material.-Storln.^ and lYeliminary Operatiojis.-Haclcling.—Sorting.—Preparing.-Tow Carding — low and Mixfn"' Combiiig —Gill Spinning.—The Roving Frame.—Dry and Demi-sec Spinning Spinning.— —Wet Spinning Waste.—Yarn Reeling.—Mauulacture ol Threads, Twines Cords.— and Pvope Making.—The Mechanical Department.—Modern Mill Construction. bteam and Water Power. —Power Transmission. " Meets the requirements of the Mill Manager or Advanced Student in a manner perhaps more than satisfactory. . . We must highly commend the work as repre- senting up-to-date practice." Nature.

In Large 8vo, Handsome Cloth, with Numerous Illustrations. 9s net TEXTILE FIBRES OF COMMERCE. A HANDBOOK OF The Occurrence, Distribution, Preparation, and Industrial Uses of the Animal, Vegetable, and Mineral Products used in Spinning and Weaving.

By WILLIAM I. HANNAN, Lecturer on Bobinyatfhe Ashton Municipal Tecbnical School, Lecturer on Cottou Spinning at the Ohorley Science and Art School, &c. With Numerous Photo Engravings from Nat^ue.

Information. , . . "Useful Admirable Iildsteations. . . . The information is not easily attainable, and in its present convenieut form will be valuable." Textv Recorder.

In Large 8vo, with Illustrations and Printed Patterns. Price TEXTILE PRINTING:21s. A PRACTICAL MANUAL. Including the Processes Used in the Printing of COTTON, WOOLLEN, SILK, and HALF- SILK FABRICS. By C. F. SEYMOUR ROTHWELL, F.C.S,, ifem. Soc, of Chemical Industries; late Lecturer at the Municipal Technical School, Manciiester. General Contents. — Introduction. — The Machinery Used in Textile Printing. —Thickeners and Mordants. —The Printing of Cotton Goods.—The Steam Style. —Colours Produced Directly on the Fibre. —Dyed Styles. Padding Style. —Resist and Discharge Styles. —The Printing of Compound Colourings, &c. —The Printing of Woollen Goods. —The Printing of Silk Goods.— Practical Recipes for Printing.— Useful Tables.— Patterns. *' By far the best and momt pkactical book on textile priktinq which has yet been brought out, and will long remain the standard work on the subject. It is essentially practical in character." Textile Mercury. " The most practical manual of textile printing which has yet appeared. We have no hesitation in recommending it." The Textile iVlanufacturer.

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-84 CHARLES GRIFFIN

Large 8vo. Handsome Cloth. 12a. 6d. BLEACHING & CALICO-PRINTING. A Short Manual for Students and Practical Men. By GEORGE DUERR, Director of the Bleaching, Dyeing, and Printing Department at the Accrington and Bacup

Technical Schooia ; Chemist and Colourist at the Irwetl Print Works. Assisted by WILLIAM TURNBULL (of Tumbull & Stockdale, Limited).

' W^ith Illustrations and upwards of One Hundred Dyed and Printed Patterns designed specially to show various Stages of the Processes described.

GENERAL CONTENTS. -Cotton, Composition of; Bleaching, New

Processes ; Printing, Hand-Block ; Flat-Press "Work ; Machine Printing

"Mordants—Styles ojt Galico-Printing : The Dyed or Madder Style, Resist Padded Style, Discharge and Extract Style, Chromed or Raised Colours, Insoluble Colours, fee. — Thickeners — Natural Organic Colouring Matters —Tannin Matters — Oils, Soaps, Solvents — Organic Acids — Salts — Mineral 'Colours—Coal Tar Colours—Dyeing—Water, Softening of—Theory of Colours —Weights and Measures, &c.

*' When a eeadt wat oat of a difficulty is wanted, it if books like this that it is found."— Textile Recorder.

"Mr. Ddbee's work will be found most dsepul. . , . The information given is of ghbat

• 7ALUE. . . . The Recipes are thoeoughly paACTiCAL."— Terrttle Manufacturer.

Second Edition. Revised and Enlarged. With Numerous GARMENTIllustrations. 4s. 6d. DYEING AND CLEANING. A Practical Book for Practical Men. By GEORGE H. HURST, F.C.S., Member of the Society of Chemical Industry.

General Contents. —Technology of the Textile Fibres—Garment Cleaning —Dyeing of Textile Fabrics—Bleaching—Finishing of Dyed and Cleaned Fabrics Scouring and Dyeing of Skin Rugs and Mats—Cleaning and Dyeing of Feathers Glove Cleaning and Dyeing—Straw Bleaching and Dyeing—Glossary of Drugs and Chemicals—Useful Tables. # " An UP-TO-DATE hand book has long been wanted, and Mr. Hurst has done nothmg more complete than this. An important work, the more so that several of the branches of the craft here treated upon are almost entirely without English Manuals for the guidance of workery. The price brings it within the reach of all." Dyer and Calico- Pri?iter. " Mr. Hurst's worK decidedly fills a want . , ought to be in the hands of EVERY garment DYER and cleaner iu the Kingdom" Textile Mercury.

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INTRODUCTORY SGIENGB SERIES. 85

"Boys OO0LD NOT HATE A MORE ALLTJKINQ INTEODCOTION tO SCienti&C pOTBUltS than these charming-looking volumes. "--Letter to the Publishers from the Head- -m aster of one of our great Public Schools.

Handsome Cloth, la. 6d. Gilt, for Presentation, Sa. 6d. OPEfl-ftlH STUDIES lU BOTflllY: SKETCHES OP BRITISH WILD FLOWERS IN THEIR HOMES. By R. LLOYD PRAEGER, B.A., M.R.I.A. Illustrated by Drawings from Nature by S. Rosamond Praeger, and Photographs by R. Welch. General Contents. —A Daisy-Starred Pasture—Under the Hawthorns —By the River—Along the Shingle—A Fragrant Hedgerow—A Connemara Bog—Where the Samphire grows—A Flowery Meadow—Among the Com (a Study in Weeds)—In the Home of the Alpines—A City Rubbish-Heap •Glossary.

" STIMUIiATINQ book . . Should A FRESH AND take a high place . . . The Illastrations are drawn with much skill." The Times.

"Beautifully illdsteatbd. . . . One of the most aoookatb as well as INTERESTING books Of the kind we have aeeu."—Ath£nceum. "Uedolent with the scent of woodland and meadow." The SUindard.

i/Vith 12 Full-Page Illustrations from Photographs. Cloth. Second Edition, Revised. 8s. da.

OPEH-fllR STUDIES IJi GEOLOGY: An Introduction to Geology Out-of-doors. By GRENVILLE A. J. COLE, F.G.S., M.R.I.A., Professor of Geology in the Royal College of Science for Ireland, and Examiner in the University of London. General Contents. —The Materials of the Earth—A Mountain Hollow —Down the Valley—Along the Shore—Across the Plains—Dead Volcanoes —A Gianite Highland—The Annals of the Earth—The Surrey Hills—The Folds of the Mountains.

" ' The FASCINATING OpBN- AiR STUDIES ' of Pkof. Oole give tbe subject a glow of

.AHIHATIOH . . . cannot fail to arouse keen interest in geology." Geological MagaziTie. "A CHARMING book, beautifully illustrated." — .<4(Aen«u77i.

Beautifully Illustrated. With a Frontispiece in Colours, and Numerous Specially Drawn Plates by Charles Whymper. 7s. 6d.

OPEH-JIIH STUDIES III BIRD-LIFE: SKETCHES OF BRITISH BIRDS IN THEIR HAUNTS. By CHARLES DIXON. The Spacious Air. —The Open Fields and Downs. —In the Hedgerows. —On Open ;Heath and Moor.—On the Mountains.—Amongst the Evergreens. Copse and Woodland. —By Stream and Pool. —The Sandy Wastes and Mud- flats. —Sea-laved Rocks.—Birds of the Cities. Index. "Enriched with excellent illustrations. A welcome addition to all libraries.'' West- tntnster Review.

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86 GEABLES GRIFFIN

Twenty-second Annual Issue. Handsome cloth, 7s. 6d.

(To Subscribers, 6s.) . THE OFFICIAL YEAR-BOOK OF THE SCIENTIFIC AND LEARNED SOCIETIES OF GREAT BRITAIN AND IRELAND. COMPILED FROM OFFICIAL SOURCES.

GompHsing (together with other Official information) LISTS of the PAPERS read during the Session 1904-1905 before ail the LEADINQ SOCIETIES throughout the Kingdom engaged in the folloufing Depart- ments of Research —

6. § I. Sdence Generally : i.e.. Societies occupy- Economic Science and Statistics. ing themselves with several Branches of 7. Mechanical Science, Engineering, and Science, or with Science and Literature Architecture jointly. § 8. Naval and Military Science. § 2. Mathematics and Physics. § g. Agriculture and Horticulture. § 3. Chemistry and Photography._ § ro. Law. S 4. Geology, Geography, and Mineralogy. § II. Literature. 12. § s. Biology, including Microscopy and An- § Psychology. thropology. § 13. Archaeology.

§ 14. Medicine.

"Fills a very real want."— Engineeri7ig. " Indispensable to any one who may wish to keep himself abreast of the scientific work of the day." Edinburgh Medical Journal. " The Ykar-Book of Societies is a Record which ought to be of the greatest use for the progress of Science."—Z.7r<^ Play/air, F.R.S., K.C.B., M.P., Past-President oftfu British Association. " It goes almost without saying that a Handbook of this subject will be in time one of the most generally useful works for the library or the desk." The Times. "British Societies are now well repreaentea In the 'Year-Book of the Scientific and Learned Societies of Great Britam and Ireland.'"—(Art. "Societies" in New Edition of "Encyclopaedia Britannica," vol. xxii.)

Copies of the First Issue, giving an Account of the History, Organization, and Conditions of Membership of the various Societies, and forming the groundwork of the Series, may still be had, price 7/6- Also Copies of the Issues following.

The YHAR-BOOK OF SOCIETIES forms a complete index ToyHE scientific work of the sessional year in the various Departments. It is used as a Handbook in all our great Scientific Gentses, Museums, and Libraries throughout the Kingdom, and has become an INDISPENSABLE BOOK OF REFERENCE to every One engaged in Scientific Work. READY IN OCTOBER EACH YEAR.

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